diff --git a/CMakeLists.txt b/CMakeLists.txt
index de77160e7..504a563e3 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -184,15 +184,11 @@ endif()
 #                      Option         Description                                Def.  Condition     Otherwise
 #                      ------         -----------                                ----  ------------  ---------
 cmake_dependent_option(AMD_K5         "AMD K5"                                   ON    "DEV_BRANCH"  OFF)
-cmake_dependent_option(AN430TX        "Intel AN430TX"                            ON    "DEV_BRANCH"  OFF)
 cmake_dependent_option(CDROM_MITSUMI  "Mitsumi CDROM"                            ON    "DEV_BRANCH"  OFF)
 cmake_dependent_option(G100           "Matrox Productiva G100"                   ON    "DEV_BRANCH"  OFF)
-cmake_dependent_option(GUSMAX         "Gravis UltraSound MAX"                    ON    "DEV_BRANCH"  OFF)
 cmake_dependent_option(ISAMEM_RAMPAGE "AST Rampage"                              ON    "DEV_BRANCH"  OFF)
 cmake_dependent_option(ISAMEM_IAB     "Intel Above Board"                        ON    "DEV_BRANCH"  OFF)
 cmake_dependent_option(ISAMEM_BRAT    "BocaRAM/AT"                               ON    "DEV_BRANCH"  OFF)
-cmake_dependent_option(OLIVETTI       "Olivetti M290"                            ON    "DEV_BRANCH"  OFF)
-cmake_dependent_option(OPEN_AT        "OpenAT"                                   ON    "DEV_BRANCH"  OFF)
 cmake_dependent_option(OPL4ML         "OPL4-ML daughterboard"                    ON    "DEV_BRANCH"  OFF)
 cmake_dependent_option(PCL            "Generic PCL5e Printer"                    ON    "DEV_BRANCH"  OFF)
 cmake_dependent_option(SIO_DETECT     "Super I/O Detection Helper"               ON    "DEV_BRANCH"  OFF)
diff --git a/src/chipset/CMakeLists.txt b/src/chipset/CMakeLists.txt
index 7d17b9983..7817ac052 100644
--- a/src/chipset/CMakeLists.txt
+++ b/src/chipset/CMakeLists.txt
@@ -18,6 +18,7 @@
 add_library(chipset OBJECT
     82c100.c
     acc2168.c
+    cs8220.c
     cs8230.c
     ali1429.c
     ali1435.c
@@ -42,6 +43,7 @@ add_library(chipset OBJECT
     isa486c.c
     ../ioapic.c
     neat.c
+    olivetti_eva.c
     opti283.c
     opti291.c
     opti391.c
@@ -85,7 +87,3 @@ add_library(chipset OBJECT
     vl82c480.c
     wd76c10.c
 )
-
-if(OLIVETTI)
-    target_sources(chipset PRIVATE olivetti_eva.c)
-endif()
diff --git a/src/chipset/ali1409.c b/src/chipset/ali1409.c
index 5009a6505..619843cda 100644
--- a/src/chipset/ali1409.c
+++ b/src/chipset/ali1409.c
@@ -61,91 +61,238 @@ ali1409_log(const char *fmt, ...)
 #endif
 
 typedef struct ali_1409_t {
-    uint8_t is_g;
     uint8_t index;
     uint8_t cfg_locked;
-    uint8_t reg_57h;
     uint8_t regs[256];
+    uint8_t shadow[4];
     uint8_t last_reg;
 } ali1409_t;
 
+/*
+   This here is because from the two BIOS'es I used to reverse engineer this,
+   it is unclear which of the two interpretations of the shadow RAM register
+   operation is correct.
+   The 16 kB interpretation appears to work fine right now but it may be wrong,
+   so I left the 32 kB interpretation in as well.
+ */
+#ifdef INTERPRETATION_32KB
+#define SHADOW_SIZE 0x00008000
+#else
+#define SHADOW_SIZE 0x00004000
+#endif
+
+static void
+ali1409_shadow_recalc(ali1409_t *dev)
+{
+    uint32_t base = 0x000c0000;
+
+    for (uint8_t i = 0; i < 4; i++) {
+        uint8_t reg = 0x08 + i;
+
+#ifdef INTERPRETATION_32KB
+        for (uint8_t j = 0; j < 4; j += 2) {
+            uint8_t mask = (0x03 << j);
+#else
+        for (uint8_t j = 0; j < 4; j++) {
+            uint8_t mask = (0x01 << j);
+#endif
+            uint8_t r_on  = dev->regs[reg] & 0x10;
+            uint8_t w_on  = dev->regs[reg] & 0x20;
+            uint8_t val   = dev->regs[reg] & mask;
+            uint8_t xor   = (dev->shadow[i] ^ dev->regs[reg]) & (mask | 0x30);
+            int     read  = r_on ? MEM_READ_INTERNAL : MEM_READ_EXTANY;
+            int     write = w_on ? MEM_WRITE_INTERNAL : MEM_WRITE_EXTANY;
+
+            if (xor) {
+#ifdef INTERPRETATION_32KB
+                switch (val >> j) {
+                    case 0x00:
+                        mem_set_mem_state_both(base, SHADOW_SIZE, MEM_READ_EXTANY | MEM_WRITE_EXTANY);
+                        break;
+                    case 0x01:
+                        mem_set_mem_state_both(base, SHADOW_SIZE, MEM_READ_EXTANY | write);
+                        break;
+                    case 0x02:
+                        mem_set_mem_state_both(base, SHADOW_SIZE, read | write);
+                        break;
+                    case 0x03:
+                        mem_set_mem_state_both(base, SHADOW_SIZE, read | MEM_WRITE_EXTANY);
+                        break;
+                }
+#else
+                switch (val >> j) {
+                    case 0x00:
+                        mem_set_mem_state_both(base, SHADOW_SIZE, MEM_READ_EXTANY | MEM_WRITE_EXTANY);
+                        break;
+                    case 0x01:
+                        mem_set_mem_state_both(base, SHADOW_SIZE, read | write);
+                        break;
+                }
+#endif
+            }
+
+            base += SHADOW_SIZE;
+        }
+
+        dev->shadow[i] = dev->regs[reg];
+    }
+
+    flushmmucache_nopc();
+}
 
 static void
 ali1409_write(uint16_t addr, uint8_t val, void *priv)
 {
     ali1409_t *dev = (ali1409_t *) priv;
-    ali1409_log ("INPUT:addr %02x ,Value %02x \n" , addr , val);
+    ali1409_log("[%04X:%08X] [W] %04X = %02X\n", CS, cpu_state.pc, addr, val);
 
-    if (addr & 1) {
-                if (dev->cfg_locked) {
-                        if (dev->last_reg == 0x14 && val == 0x09)
-                                dev->cfg_locked = 0;
+    if (addr & 0x0001) {
+        if (dev->cfg_locked) {
+            if ((dev->last_reg == 0x14) && (val == 0x09))
+                dev->cfg_locked = 0;
 
-                        dev->last_reg = val;
-                        return;
-                }
+            dev->last_reg = val;
+            return;
+        }
 
-                if (dev->index == 0xff && val == 0xff)
-                        dev->cfg_locked = 1;
-                else {
-                        ali1409_log("Write reg %02x %02x %08x\n", dev->index, val, cs);
-                        dev->regs[dev->index] = val;
+        /* It appears writing anything at all to register 0xFF locks it again. */
+        if (dev->index == 0xff)
+            dev->cfg_locked = 1;
+        else if (dev->index < 0x44) {
+            ali1409_log("[%04X:%08X] [W] Register %02X = %02X\n", CS, cpu_state.pc, dev->index, val);
 
-                        switch (dev->index) {
-                        case 0xa:
-                                switch ((val >> 4) & 3) {
-                                case 0:
-                                        mem_set_mem_state(0xe0000, 0x10000, MEM_READ_EXTERNAL | MEM_WRITE_EXTERNAL);
-                                        break;
-                                case 1:
-                                        mem_set_mem_state(0xe0000, 0x10000, MEM_READ_INTERNAL | MEM_WRITE_EXTERNAL);
-                                        break;
-                                case 2:
-                                        mem_set_mem_state(0xe0000, 0x10000, MEM_READ_EXTERNAL | MEM_WRITE_INTERNAL);
-                                        break;
-                                case 3:
-                                        mem_set_mem_state(0xe0000, 0x10000, MEM_READ_INTERNAL | MEM_WRITE_INTERNAL);
-                                        break;
-                                }
+            if (dev->index < 0x10) { 
+                dev->regs[dev->index] = val;
+
+                /*
+                   There are still a lot of unknown here, but unfortunately, this is
+                   as far as I have been able to come with two BIOS'es that are
+                   available (the Acer 100T and an AMI Color dated 07/07/91).
+                 */
+                switch (dev->index) {
+                    case 0x02:
+                        /*
+                           - Bit 7: The RAS address hold time:
+                               - 0: 1/2 T;
+                               - 1: 1 T.
+                           - Bits 6-4: The RAS precharge time:
+                               - 0, 0, 0: 1.5 T;
+                               - 0, 0, 1: 2 T;
+                               - 0, 1, 0: 2.5 T;
+                               - 0, 1, 1: 3 T;
+                               - 1, 0, 0: 3.5 T;
+                               - 1, 0, 1: 4 T;
+                               - 1, 1, 0: Reserved;
+                               - 1, 1, 1: Reserved.
+                           - Bit 3: Early miss cycle:
+                               - 0: Disabled;
+                               - 1: Enabled.
+                         */
+                        break;
+                    case 0x03:
+                        /*
+                           - Bit 6: CAS pulse for read cycle:
+                               - 0: 1 T;
+                               - 1: 1.5 T or 2 T.
+                               I can not get the 2.5 T or 3 T setting to apply so
+                               I have no idea what bit governs that.
+                           - Bits 5, 4: CAS pulse for write cycle:
+                               - 0, 0: 0.5 T or 1 T;
+                               - 0, 1: 1.5 T or 2 T;
+                               - 1, 0: 2.5 T or 3 T;
+                               - 1, 1: Reserved.
+                           - Bit 3: CAS active for read cycle:
+                               - 0: Disabled;
+                               - 1: Enabled.
+                           - Bit 2: CAS active for write cycle:
+                               - 0: Disabled;
+                               - 1: Enabled.
+                         */
+                        break;
+                    case 0x06:
+                        /*
+                           - Bits 6-4: Clock divider:
+                               - 0, 0, 0: / 2;
+                               - 0, 0, 1: / 4;
+                               - 0, 1, 0: / 8;
+                               - 0, 1, 1: Reserved;
+                               - 1, 0, 0: / 3;
+                               - 1, 0, 1: / 6;
+                               - 1, 1, 0: / 5;
+                               - 1, 1, 1: / 10.
+                         */
+                        switch ((val >> 4) & 7) {
+                            default:
+                            case 3: /* Reserved */
+                                cpu_set_isa_speed(7159091);
                                 break;
-                        case 0xb:
-                                switch ((val >> 4) & 3) {
-                                case 0:
-                                        mem_set_mem_state(0xf0000, 0x10000, MEM_READ_EXTANY | MEM_WRITE_EXTANY);
-                                        break;
-                                case 1:
-                                        mem_set_mem_state(0xf0000, 0x10000, MEM_READ_INTERNAL | MEM_WRITE_EXTANY);
-                                        break;
-                                case 2:
-                                        mem_set_mem_state(0xf0000, 0x10000, MEM_READ_EXTANY| MEM_WRITE_INTERNAL);
-                                        break;
-                                case 3:
-                                        mem_set_mem_state(0xf0000, 0x10000, MEM_READ_INTERNAL | MEM_WRITE_INTERNAL);
-                                        break;
-                                }
+
+                            case 0:
+                                cpu_set_isa_speed(cpu_busspeed / 2);
+                                break;
+
+                            case 1:
+                                cpu_set_isa_speed(cpu_busspeed / 4);
+                                break;
+
+                            case 2:
+                                cpu_set_isa_speed(cpu_busspeed / 8);
+                                break;
+
+                            case 4:
+                                cpu_set_isa_speed(cpu_busspeed / 3);
+                                break;
+
+                            case 5:
+                                cpu_set_isa_speed(cpu_busspeed / 6);
+                                break;
+
+                            case 6:
+                                cpu_set_isa_speed(cpu_busspeed / 5);
+                                break;
+
+                            case 7:
+                                cpu_set_isa_speed(cpu_busspeed / 10);
                                 break;
                         }
+                        break;
+                    case 0x08 ... 0x0b:
+                        ali1409_shadow_recalc(dev);
+                        break;
+                    case 0x0c:
+                        /*
+                           This appears to be turbo in bit 4 (1 = on, 0 = off),
+                           and bus speed in the rest of the bits.
+                         */
+                        break;
+                    case 0x0d:
+                        cpu_cache_ext_enabled = !!(val & 0x08);
+                        cpu_update_waitstates();
+                        break;
                 }
-        } else
-                dev->index = val;
+            }
+        }
+    } else
+        dev->index = val;
 }
 
 
 static uint8_t
 ali1409_read(uint16_t addr, void *priv)
 {
-    ali1409_log ("reading at %02X\n",addr);
     const ali1409_t *dev = (ali1409_t *) priv;
     uint8_t          ret = 0xff;
 
     if (dev->cfg_locked)
          ret = 0xff;
-    if (addr & 1) {
-        if ((dev->index >= 0xc0 || dev->index == 0x20) && cpu_iscyrix)
-                 ret = 0xff; 
+    else if (addr & 0x0001) {
+        if (dev->index < 0x44)
             ret = dev->regs[dev->index];
-        } else
-                ret = dev->index;
+    } else
+        ret = dev->index;
+
+    ali1409_log("[%04X:%08X] [R] %04X = %02X\n", CS, cpu_state.pc, addr, ret);
+
     return ret;
 }
 
@@ -166,17 +313,16 @@ ali1409_init(UNUSED(const device_t *info))
 
     dev->cfg_locked = 1;
 
-    /* M1409 Ports:
-                22h	Index Port
-                23h	Data Port
-    */
-   
-    ali1409_log ("Bus speed: %i", cpu_busspeed);
-   
+    ali1409_log("Bus speed: %i\n", cpu_busspeed);
 
     io_sethandler(0x0022, 0x0002, ali1409_read, NULL, NULL, ali1409_write, NULL, NULL, dev);
-    io_sethandler(0x037f, 0x0001, ali1409_read, NULL, NULL, ali1409_write, NULL, NULL, dev);
-    io_sethandler(0x03f3, 0x0001, ali1409_read, NULL, NULL, ali1409_write, NULL, NULL, dev);
+
+    dev->regs[0x0f] = 0x08;
+
+    cpu_set_isa_speed(7159091);
+
+    cpu_cache_ext_enabled = 0;
+    cpu_update_waitstates();
 
     return dev;
 }
diff --git a/src/chipset/cs8220.c b/src/chipset/cs8220.c
new file mode 100644
index 000000000..4c08ecef5
--- /dev/null
+++ b/src/chipset/cs8220.c
@@ -0,0 +1,289 @@
+/*
+ * 86Box    A hypervisor and IBM PC system emulator that specializes in
+ *          running old operating systems and software designed for IBM
+ *          PC systems and compatibles from 1981 through fairly recent
+ *          system designs based on the PCI bus.
+ *
+ *          This file is part of the 86Box distribution.
+ *
+ *          Emulation of C&T CS8220 ("PC/AT") chipset.
+ *
+ * Authors: Miran Grca, <mgrca8@gmail.com>
+ *
+ *          Copyright 2025 Miran Grca.
+ */
+#include <stdio.h>
+#include <stdint.h>
+#include <stdlib.h>
+#include <string.h>
+#include <wchar.h>
+#include <86box/86box.h>
+#include "cpu.h"
+#include <86box/timer.h>
+#include <86box/io.h>
+#include <86box/device.h>
+#include <86box/machine.h>
+#include <86box/mem.h>
+#include <86box/plat_fallthrough.h>
+#include <86box/plat_unused.h>
+#include <86box/fdd.h>
+#include <86box/fdc.h>
+#include <86box/chipset.h>
+
+typedef struct {
+    uint32_t      virt;
+    uint32_t      phys;
+
+    uint32_t      size;
+
+    mem_mapping_t mapping;
+} ram_bank_t;
+
+typedef struct {
+    uint8_t       regs[3];
+
+    ram_bank_t    ram_banks[3];
+} cs8220_t;
+
+static uint8_t
+cs8220_mem_read(uint32_t addr, void *priv)
+{
+    ram_bank_t *dev = (ram_bank_t *) priv;
+    uint8_t     ret = 0xff;
+
+    addr = (addr - dev->virt) + dev->phys;
+
+    if (addr < (mem_size << 10))
+        ret = ram[addr];
+
+    return ret;
+}
+
+static uint16_t
+cs8220_mem_readw(uint32_t addr, void *priv)
+{
+    ram_bank_t *dev = (ram_bank_t *) priv;
+    uint16_t    ret = 0xffff;
+
+    addr = (addr - dev->virt) + dev->phys;
+
+    if (addr < (mem_size << 10))
+        ret = *(uint16_t *) &(ram[addr]);
+
+    return ret;
+}
+
+static void
+cs8220_mem_write(uint32_t addr, uint8_t val, void *priv)
+{
+    ram_bank_t *dev = (ram_bank_t *) priv;
+
+    addr = (addr - dev->virt) + dev->phys;
+
+    if (addr < (mem_size << 10))
+        ram[addr] = val;
+}
+
+static void
+cs8220_mem_writew(uint32_t addr, uint16_t val, void *priv)
+{
+    ram_bank_t *dev = (ram_bank_t *) priv;
+
+    addr = (addr - dev->virt) + dev->phys;
+
+    if (addr < (mem_size << 10))
+        *(uint16_t *) &(ram[addr]) = val;
+}
+
+static uint8_t
+cs8220_in(uint16_t port, void *priv) {
+    cs8220_t *dev = (cs8220_t *) priv;
+    uint8_t   ret = 0xff;
+
+    switch (port) {
+        case 0x00a4 ... 0x00a5:
+            ret = dev->regs[port & 0x0001];
+            break;
+        case 0x00ab:
+            ret = dev->regs[2];
+            break;
+    }
+
+    return ret;
+}
+
+static void
+cs8220_out(uint16_t port, uint8_t val, void *priv) {
+    cs8220_t *dev = (cs8220_t *) priv;
+
+    switch (port) {
+        case 0x00a4:
+            dev->regs[0] = val;
+            mem_a20_alt = val & 0x40;
+            mem_a20_recalc();
+            break;
+        case 0x00a5:
+            dev->regs[1] = val;
+            if (val & 0x01) {
+                mem_mapping_set_addr(&dev->ram_banks[0].mapping, 0, 0x000040000);
+                mem_mapping_disable(&dev->ram_banks[1].mapping);
+                mem_mapping_disable(&dev->ram_banks[2].mapping);
+            } else {
+                mem_mapping_set_addr(&dev->ram_banks[0].mapping, 0, dev->ram_banks[0].size);
+                mem_mapping_enable(&dev->ram_banks[1].mapping);
+                mem_mapping_enable(&dev->ram_banks[2].mapping);
+            }
+            break;
+        case 0x00ab:
+            dev->regs[2] = val;
+            break;
+    }
+}
+
+static void
+cs8220_close(void *priv)
+{
+    cs8220_t *dev = (cs8220_t *) priv;
+
+    free(dev);
+}
+
+static void *
+cs8220_init(UNUSED(const device_t *info))
+{
+    cs8220_t *dev = (cs8220_t *) calloc(1, sizeof(cs8220_t));
+
+    mem_mapping_disable(&ram_low_mapping);
+    mem_mapping_disable(&ram_mid_mapping);
+    mem_mapping_disable(&ram_high_mapping);
+
+    /*
+       Dell System 200: 640 kB soldered on-board, any other RAM is expansion.
+     */
+    if (!strcmp(machine_get_internal_name(), "dells200"))  switch (mem_size) {
+        default:
+            dev->ram_banks[2].virt = 0x00100000;
+            dev->ram_banks[2].phys = 0x000a0000;
+            dev->ram_banks[2].size = (mem_size << 10) - 0x000a0000;
+            fallthrough;
+        case 640:
+            dev->ram_banks[0].virt = 0x00000000;
+            dev->ram_banks[0].phys = 0x00000000;
+            dev->ram_banks[0].size = 0x00080000;
+            dev->ram_banks[1].virt = 0x00080000;
+            dev->ram_banks[1].phys = 0x00080000;
+            dev->ram_banks[1].size = 0x00020000;
+            break;
+    /*
+       We are limited to steps of equal size, so we have to simulate some
+       memory expansions to work around the chipset's limits.
+     */
+    } else  switch (mem_size) {
+        case 256:
+            dev->ram_banks[0].virt = 0x00000000;
+            dev->ram_banks[0].phys = 0x00000000;
+            dev->ram_banks[0].size = 0x00020000;
+            dev->ram_banks[1].virt = 0x00020000;
+            dev->ram_banks[1].phys = 0x00020000;
+            dev->ram_banks[1].size = 0x00020000;
+            break;
+        case 384:
+            dev->ram_banks[0].virt = 0x00000000;
+            dev->ram_banks[0].phys = 0x00000000;
+            dev->ram_banks[0].size = 0x00020000;
+            /* Pretend there's a 128k expansion. */
+            dev->ram_banks[2].virt = 0x00020000;
+            dev->ram_banks[2].phys = 0x00020000;
+            dev->ram_banks[2].size = 0x00040000;
+            break;
+        case 512:
+            dev->ram_banks[0].virt = 0x00000000;
+            dev->ram_banks[0].phys = 0x00000000;
+            dev->ram_banks[0].size = 0x00080000;
+            break;
+        default:
+            dev->ram_banks[2].virt = 0x00100000;
+            dev->ram_banks[2].phys = 0x000a0000;
+            dev->ram_banks[2].size = (mem_size << 10) - 0x000a0000;
+            fallthrough;
+        case 640:
+            dev->ram_banks[0].virt = 0x00000000;
+            dev->ram_banks[0].phys = 0x00000000;
+            dev->ram_banks[0].size = 0x00080000;
+            dev->ram_banks[1].virt = 0x00080000;
+            dev->ram_banks[1].phys = 0x00080000;
+            dev->ram_banks[1].size = 0x00020000;
+            break;
+        case 768:
+            dev->ram_banks[0].virt = 0x00000000;
+            dev->ram_banks[0].phys = 0x00000000;
+            dev->ram_banks[0].size = 0x00080000;
+            dev->ram_banks[1].virt = 0x00080000;
+            dev->ram_banks[1].phys = 0x00080000;
+            dev->ram_banks[1].size = 0x00020000;
+            /* Pretend there's a 128k expansion. */
+            dev->ram_banks[2].virt = 0x00100000;
+            dev->ram_banks[2].phys = 0x00080000;
+            dev->ram_banks[2].size = 0x00020000;
+            break;
+        case 896:
+            dev->ram_banks[0].virt = 0x00000000;
+            dev->ram_banks[0].phys = 0x00000000;
+            dev->ram_banks[0].size = 0x00080000;
+            dev->ram_banks[1].virt = 0x00080000;
+            dev->ram_banks[1].phys = 0x00080000;
+            dev->ram_banks[1].size = 0x00020000;
+            /* Pretend there's a 256k expansion. */
+            dev->ram_banks[2].virt = 0x00100000;
+            dev->ram_banks[2].phys = 0x00080000;
+            dev->ram_banks[2].size = 0x00040000;
+            break;
+        case 1024:
+            dev->ram_banks[0].virt = 0x00000000;
+            dev->ram_banks[0].phys = 0x00000000;
+            dev->ram_banks[0].size = 0x00080000;
+            dev->ram_banks[1].virt = 0x00100000;
+            dev->ram_banks[1].phys = 0x00080000;
+            dev->ram_banks[1].size = 0x00080000;
+            break;
+    }
+
+    if (dev->ram_banks[0].size > 0x00000000)
+        mem_mapping_add(&dev->ram_banks[0].mapping, dev->ram_banks[0].virt, dev->ram_banks[0].size,
+                        cs8220_mem_read, cs8220_mem_readw, NULL,
+                        cs8220_mem_write, cs8220_mem_writew, NULL,
+                        ram + dev->ram_banks[0].phys, MEM_MAPPING_INTERNAL, &(dev->ram_banks[0]));
+
+    if (dev->ram_banks[1].size > 0x00000000)
+        mem_mapping_add(&dev->ram_banks[1].mapping, dev->ram_banks[1].virt, dev->ram_banks[1].size,
+                        cs8220_mem_read, cs8220_mem_readw, NULL,
+                        cs8220_mem_write, cs8220_mem_writew, NULL,
+                        ram + dev->ram_banks[1].phys, MEM_MAPPING_INTERNAL, &(dev->ram_banks[1]));
+
+    if (dev->ram_banks[2].size > 0x00000000)
+        mem_mapping_add(&dev->ram_banks[2].mapping, dev->ram_banks[2].virt, dev->ram_banks[2].size,
+                        cs8220_mem_read, cs8220_mem_readw, NULL,
+                        cs8220_mem_write, cs8220_mem_writew, NULL,
+                        ram + dev->ram_banks[2].phys, MEM_MAPPING_INTERNAL, &(dev->ram_banks[2]));
+
+    io_sethandler(0x00a4, 0x0002,
+                  cs8220_in, NULL, NULL, cs8220_out, NULL, NULL, dev);
+    io_sethandler(0x00ab, 0x0001,
+                  cs8220_in, NULL, NULL, cs8220_out, NULL, NULL, dev);
+
+    return dev;
+}
+
+const device_t cs8220_device = {
+    .name          = "C&T CS8220 (PC/AT)",
+    .internal_name = "cs8220",
+    .flags         = 0,
+    .local         = 0,
+    .init          = cs8220_init,
+    .close         = cs8220_close,
+    .reset         = NULL,
+    .available     = NULL,
+    .speed_changed = NULL,
+    .force_redraw  = NULL,
+    .config        = NULL
+};
diff --git a/src/chipset/intel_4x0.c b/src/chipset/intel_4x0.c
index 84bd872f8..8e6ce97c3 100644
--- a/src/chipset/intel_4x0.c
+++ b/src/chipset/intel_4x0.c
@@ -1013,7 +1013,8 @@ i4x0_write(int func, int addr, uint8_t val, void *priv)
                     case INTEL_430TX:
                         if (!dev->smram_locked) {
                             i4x0_smram_handler_phase0(dev);
-                            regs[0x71] = (regs[0x71] & 0x20) | (val & 0xdf);
+                            regs[0x71] = (regs[0x71] & 0x60) | (val & 0x9f);
+                            regs[0x71] &= (val & 0x40);
                             i4x0_smram_handler_phase1(dev);
                         }
                         break;
@@ -1041,9 +1042,11 @@ i4x0_write(int func, int addr, uint8_t val, void *priv)
                             regs[0x72] = (val & 0x7f);
                         else
                             regs[0x72] = (regs[0x72] & 0x87) | (val & 0x78);
-                        dev->smram_locked = (val & 0x10);
-                        if (dev->smram_locked)
-                            regs[0x72] &= 0xbf;
+                        if (val & 0x08) {
+                            dev->smram_locked = (val & 0x10);
+                            if (dev->smram_locked)
+                                regs[0x72] &= 0xbf;
+                        }
                     }
                 } else {
                     if (dev->smram_locked)
@@ -1577,6 +1580,8 @@ i4x0_reset(void *priv)
             dev->regs[0x68 + i] = 0x00;
     }
 
+    dev->smram_locked = 0;
+
     if (dev->type >= INTEL_430FX) {
         dev->regs[0x72] &= 0xef; /* Forcibly unlock the SMRAM register. */
         i4x0_write(0, 0x72, 0x02, priv);
diff --git a/src/chipset/olivetti_eva.c b/src/chipset/olivetti_eva.c
index 7defac6ae..0dcbdd21f 100644
--- a/src/chipset/olivetti_eva.c
+++ b/src/chipset/olivetti_eva.c
@@ -73,26 +73,24 @@ olivetti_eva_write(uint16_t addr, uint8_t val, void *priv)
             break;
         case 0x069:
             dev->reg_069 = val;
-            /*
-             * Unfortunately, if triggered, the BIOS remapping function fails causing
-             * a fatal error. Therefore, this code section is currently commented.
-             */
-#if 0
-            if (val & 1) {
+            mem_remap_top(0);
+            if (val == 0x01) {
                 /*
                  * Set the register to 7 or above for the BIOS to trigger the
                  * memory remapping function if shadowing is active.
                  */
-                 dev->reg_069 = 0x7;
+                 dev->reg_069 = 0x07;
             }
-            if (val & 8) {
+            if (val & 0x08) {
                 /*
                  * Activate shadowing for region e0000-fffff
                  */
                  mem_remap_top(256);
-                 mem_set_mem_state_both(0xa0000, 0x60000, MEM_READ_INTERNAL | MEM_WRITE_INTERNAL);
+                 mem_set_mem_state_both(0xe0000, 0x20000, MEM_READ_INTERNAL | MEM_WRITE_INTERNAL);
+            } else {
+                 mem_remap_top(384);
+                 mem_set_mem_state_both(0xe0000, 0x20000, MEM_READ_EXTANY | MEM_WRITE_EXTANY);
             }
-#endif
             break;
         default:
             break;
@@ -143,7 +141,7 @@ olivetti_eva_init(UNUSED(const device_t *info))
     dev->reg_067 = 0x00;
 
     /* RAM enable registers */
-    dev->reg_069 = 0x0;
+    dev->reg_069 = 0x00;
 
     io_sethandler(0x0065, 0x0001, olivetti_eva_read, NULL, NULL, olivetti_eva_write, NULL, NULL, dev);
     io_sethandler(0x0067, 0x0001, olivetti_eva_read, NULL, NULL, olivetti_eva_write, NULL, NULL, dev);
@@ -152,13 +150,6 @@ olivetti_eva_init(UNUSED(const device_t *info))
     /* When shadowing is not enabled in BIOS, all upper memory is available as XMS */
     mem_remap_top(384);
 
-    /*
-     * Default settings when NVRAM is cleared activate shadowing.
-     * Thus, to avoid boot errors, remap only 256k from UMB to XMS.
-     * Remove this block once BIOS memory remapping works.
-     */
-    mem_remap_top(256);
-
     return dev;
 }
 
diff --git a/src/chipset/scamp.c b/src/chipset/scamp.c
index 8e7892c2e..855175dcd 100644
--- a/src/chipset/scamp.c
+++ b/src/chipset/scamp.c
@@ -1177,7 +1177,7 @@ scamp_init(UNUSED(const device_t *info))
             dev->mem_flags[i] = MEM_FLAG_READ | MEM_FLAG_WRITE;
             scamp_mem_update_state(dev, i * EMS_PGSIZE, EMS_PGSIZE, 0x00, MEM_FMASK_RW);
 
-            if (i >= 60)
+            if (i >= 56)
                 scamp_mem_update_state(dev, i * EMS_PGSIZE, EMS_PGSIZE, MEM_FLAG_ROMCS, MEM_FMASK_ROMCS);
         }
     }
diff --git a/src/chipset/umc_hb4.c b/src/chipset/umc_hb4.c
index 889691988..55901b32e 100644
--- a/src/chipset/umc_hb4.c
+++ b/src/chipset/umc_hb4.c
@@ -270,6 +270,8 @@ hb4_smram(hb4_t *dev)
     }
 
     umc_smram_recalc(dev->smram_base >> 12, 1);
+
+    flushmmucache();
 }
 
 static void
@@ -398,55 +400,6 @@ hb4_close(void *priv)
     free(dev);
 }
 
-static void
-ims8848_write(uint16_t addr, uint8_t val, void *priv)
-{
-    hb4_t     *dev = (hb4_t *) priv;
-
-    switch (addr) {
-        case 0x22:
-            dev->idx = val;
-            break;
-        case 0x23:
-            if (((val & 0x0f) == ((dev->idx >> 4) & 0x0f)) && ((val & 0xf0) == ((dev->idx << 4) & 0xf0)))
-                dev->access_data = 1;
-            break;
-        case 0x24:
-            if (dev->access_data)
-                dev->access_data = 0;
-            break;
-
-            default:
-                break;
-    }
-}
-
-static uint8_t
-ims8848_read(uint16_t addr, void *priv)
-{
-    uint8_t    ret = 0xff;
-    hb4_t     *dev = (hb4_t *) priv;
-
-    switch (addr) {
-        case 0x22:
-            ret = dev->idx;
-            break;
-        case 0x23:
-            ret = (dev->idx >> 4) | (dev->idx << 4);
-            break;
-        case 0x24:
-            if (dev->access_data) {
-                ret              = dev->pci_conf[dev->idx];
-                dev->access_data = 0;
-            }
-            break;
-        default:
-            break;
-    }
-
-    return ret;
-}
-
 static void *
 hb4_init(UNUSED(const device_t *info))
 {
@@ -463,8 +416,6 @@ hb4_init(UNUSED(const device_t *info))
     dev->smram_base = 0x000a0000;
     hb4_reset(dev);
 
-    io_sethandler(0x0022, 0x0003, ims8848_read, NULL, NULL, ims8848_write, NULL, NULL, dev);
-
     return dev;
 }
 
diff --git a/src/cpu/cpu.c b/src/cpu/cpu.c
index d13dfe041..ec026d95e 100644
--- a/src/cpu/cpu.c
+++ b/src/cpu/cpu.c
@@ -4264,7 +4264,7 @@ cpu_write(uint16_t addr, uint8_t val, UNUSED(void *priv))
         cyrix_addr = val;
     else if (addr < 0xf1)  switch (cyrix_addr) {
         default:
-            if (cyrix_addr >= 0xc0)
+            if ((cyrix_addr >= 0xc0) && (cyrix_addr != 0xff))
                 fatal("Writing unimplemented Cyrix register %02X\n", cyrix_addr);
             break;
 
diff --git a/src/device/kbc_at.c b/src/device/kbc_at.c
index dc93a4fba..dd2d5a636 100644
--- a/src/device/kbc_at.c
+++ b/src/device/kbc_at.c
@@ -830,7 +830,9 @@ write_p2(atkbc_t *dev, uint8_t val)
             softresetx86(); /* Pulse reset! */
             cpu_set_edx();
             flushmmucache();
-            if ((kbc_ven == KBC_VEN_ALI) || !strcmp(machine_get_internal_name(), "spc7700plw"))
+            if ((kbc_ven == KBC_VEN_ALI) ||
+                !strcmp(machine_get_internal_name(), "spc7700plw") ||
+                !strcmp(machine_get_internal_name(), "pl4600c"))
                 smbase = 0x00030000;
 
             /* Yes, this is a hack, but until someone gets ahold of the real PCD-2L
@@ -1077,7 +1079,14 @@ write_cmd_generic(void *priv, uint8_t val)
             /* The SMM handlers of Intel AMI Pentium BIOS'es expect bit 6 to be set. */
             if ((kbc_ven == KBC_VEN_AMI) && ((dev->flags & KBC_TYPE_MASK) == KBC_TYPE_GREEN))
                 fixed_bits |= 0x40;
-            if (kbc_ven == KBC_VEN_IBM_PS1) {
+            if (!strcmp(machine_get_internal_name(), "dells333sl")) {
+                /*
+                   Dell System 333s/L:
+                       - Bit 5: Stuck in reboot loop if clear.
+                 */
+                uint8_t p1 = 0x20 | (video_is_mda() ? 0x40 : 0x00);
+                kbc_delay_to_ob(dev, p1, 0, 0x00);
+            } else if (kbc_ven == KBC_VEN_IBM_PS1) {
                 current_drive = fdc_get_current_drive();
                 /* (B0 or F0) | (fdd_is_525(current_drive) on bit 6) */
                 kbc_delay_to_ob(dev, dev->p1 | fixed_bits | (fdd_is_525(current_drive) ? 0x40 : 0x00),
@@ -1112,7 +1121,7 @@ write_cmd_generic(void *priv, uint8_t val)
                        Dell 466/NP:
                            - Bit 2: Keyboard fuse (must be set);
                            - Bit 4: Password disable jumper (must be clear);
-                           - Bit 5: Manufacturing jumper (must be set);
+                           - Bit 5: Manufacturing jumper (must be set).
                      */
                     uint8_t p1 = 0x24;
                     kbc_delay_to_ob(dev, p1, 0, 0x00);
@@ -1121,7 +1130,7 @@ write_cmd_generic(void *priv, uint8_t val)
                        Dell OptiPlex GXL/GXM:
                            - Bit 3: Password disable jumper (must be clear);
                            - Bit 4: Keyboard fuse (must be set);
-                           - Bit 5: Manufacturing jumper (must be set);
+                           - Bit 5: Manufacturing jumper (must be set).
                      */
                     uint8_t p1 = 0x30;
                     kbc_delay_to_ob(dev, p1, 0, 0x00);
diff --git a/src/device/pci_bridge.c b/src/device/pci_bridge.c
index 8893acf69..bf49baf14 100644
--- a/src/device/pci_bridge.c
+++ b/src/device/pci_bridge.c
@@ -87,6 +87,14 @@ pci_bridge_set_ctl(void *priv, uint8_t ctl)
     dev->ctl = ctl;
 }
 
+uint8_t
+pci_bridge_get_bus_index(void *priv)
+{
+    pci_bridge_t *dev = (pci_bridge_t *) priv;
+
+    return dev->bus_index;
+}
+
 static void
 pci_bridge_write(int func, int addr, uint8_t val, void *priv)
 {
@@ -513,11 +521,9 @@ static void *
 pci_bridge_init(const device_t *info)
 {
     uint8_t interrupts[4];
-    uint8_t interrupt_count;
     uint8_t interrupt_mask;
+    uint8_t add_type;
     uint8_t slot_count;
-    uint8_t dell_slots[3]         = { 0x09, 0x0a, 0x0b };
-    uint8_t dell_interrupts[3][4] = { { 1, 2, 3, 4 }, { 4, 2, 1, 3 }, { 1, 3, 4, 2 } };
 
     pci_bridge_t *dev = (pci_bridge_t *) calloc(1, sizeof(pci_bridge_t));
 
@@ -527,40 +533,35 @@ pci_bridge_init(const device_t *info)
 
     pci_bridge_reset(dev);
 
-    if (info->local == PCI_BRIDGE_DEC_21152)
-        pci_add_card(PCI_ADD_BRIDGE, pci_bridge_read, pci_bridge_write, dev, &dev->slot);
-    else
-        pci_add_bridge(AGP_BRIDGE(dev->local), pci_bridge_read, pci_bridge_write, dev, &dev->slot);
-
-    interrupt_count = sizeof(interrupts);
-    interrupt_mask  = interrupt_count - 1;
+    interrupt_mask = sizeof(interrupts) - 1;
     if (dev->slot < 32) {
-        for (uint8_t i = 0; i < interrupt_count; i++)
+        for (uint8_t i = 0; i <= interrupt_mask; i++)
             interrupts[i] = pci_get_int(dev->slot, PCI_INTA + i);
     }
     pci_bridge_log("PCI Bridge %d: upstream bus %02X slot %02X interrupts %02X %02X %02X %02X\n",
                    dev->bus_index, (dev->slot >> 5) & 0xff, dev->slot & 31, interrupts[0],
                    interrupts[1], interrupts[2], interrupts[3]);
 
-    if (info->local == PCI_BRIDGE_DEC_21150)
+    if (info->local == PCI_BRIDGE_DEC_21150) {
         slot_count = 9; /* 9 bus masters */
-    else if (info->local == PCI_BRIDGE_DEC_21152)
-        slot_count = 3; /* 3 bus masters */
-    else
+        add_type   = PCI_ADD_NORMAL;
+    } else if (info->local == PCI_BRIDGE_DEC_21152) {
+        slot_count = 0; /* 4 bus masters, but slots are added by the Dell machines */
+        add_type   = PCI_ADD_BRIDGE;
+    } else {
         slot_count = 1; /* AGP bridges always have 1 slot */
+        add_type   = PCI_ADD_AGPBRIDGE;
+    }
+
+    pci_add_bridge(add_type, pci_bridge_read, pci_bridge_write, dev, &dev->slot);
 
     for (uint8_t i = 0; i < slot_count; i++) {
-        uint8_t slot = i;
-        if (info->local == PCI_BRIDGE_DEC_21152) {
-            slot = dell_slots[i];
-            memcpy(interrupts, dell_interrupts[i], 4);
-        }
         /* Interrupts for bridge slots are assigned in round-robin: ABCD, BCDA, CDAB and so on. */
         pci_bridge_log("PCI Bridge %d: downstream slot %02X interrupts %02X %02X %02X %02X\n",
-                       dev->bus_index, slot, interrupts[i & interrupt_mask],
+                       dev->bus_index, i, interrupts[i & interrupt_mask],
                        interrupts[(i + 1) & interrupt_mask], interrupts[(i + 2) & interrupt_mask],
                        interrupts[(i + 3) & interrupt_mask]);
-        pci_register_bus_slot(dev->bus_index, slot, AGP_BRIDGE(dev->local) ? PCI_CARD_AGP : PCI_CARD_NORMAL,
+        pci_register_bus_slot(dev->bus_index, i, AGP_BRIDGE(dev->local) ? PCI_CARD_AGP : PCI_CARD_NORMAL,
                               interrupts[i & interrupt_mask],
                               interrupts[(i + 1) & interrupt_mask],
                               interrupts[(i + 2) & interrupt_mask],
diff --git a/src/device/postcard.c b/src/device/postcard.c
index 19d81b692..ec031c2b8 100644
--- a/src/device/postcard.c
+++ b/src/device/postcard.c
@@ -36,6 +36,7 @@ static uint16_t postcard_port;
 static uint8_t  postcard_written[POSTCARDS_NUM];
 static uint8_t  postcard_ports_num = 1;
 static uint8_t  postcard_prev_codes[POSTCARDS_NUM];
+static uint8_t  postcard_dell_mode = 0;
 static char     postcard_prev_diags[5] = { 0 };
 #define UISTR_LEN 32
 static char postcard_str[UISTR_LEN]; /* UI output string */
@@ -99,30 +100,23 @@ postcard_setui(void)
                         ps[1][0], ps[1][1], ps[1][2], ps[1][3]);
                 break;
         }
-    } else if (strstr(machines[machine].name, " Dell ") &&
-               (machine_get_chipset(machine) >= MACHINE_CHIPSET_INTEL_430FX)) {
-        char dell_diags[10] = { 0 };
-
-        if (!postcard_written[1])
-            snprintf(dell_diags, sizeof(dell_diags), "---- ----");
-        else if (postcard_written[1] == 1)
-            snprintf(dell_diags, sizeof(dell_diags), "%s ----", postcard_diags);
-        else
-            snprintf(dell_diags, sizeof(dell_diags), "%s %s", postcard_diags, postcard_prev_diags);
-
-        if (!postcard_written[0])
-            snprintf(postcard_str, sizeof(postcard_str), "POST: -- -- %s", dell_diags);
-        else if (postcard_written[0] == 1)
-            snprintf(postcard_str, sizeof(postcard_str), "POST: %02X -- %s", postcard_codes[0], dell_diags);
-        else
-            snprintf(postcard_str, sizeof(postcard_str), "POST: %02X %02X %s", postcard_codes[0], postcard_prev_codes[0], dell_diags);
     } else {
+        char dell_diags[11] = { 0 };
+        if (postcard_dell_mode) {
+            if (!postcard_written[1])
+                snprintf(dell_diags, sizeof(dell_diags), " ---- ----");
+            else if (postcard_written[1] == 1)
+                snprintf(dell_diags, sizeof(dell_diags), " %s ----", postcard_diags);
+            else
+                snprintf(dell_diags, sizeof(dell_diags), " %s %s", postcard_diags, postcard_prev_diags);
+        }
+
         if (!postcard_written[0])
-            snprintf(postcard_str, sizeof(postcard_str), "POST: -- --");
+            snprintf(postcard_str, sizeof(postcard_str), "POST: -- --%s", dell_diags);
         else if (postcard_written[0] == 1)
-            snprintf(postcard_str, sizeof(postcard_str), "POST: %02X --", postcard_codes[0]);
+            snprintf(postcard_str, sizeof(postcard_str), "POST: %02X --%s", postcard_codes[0], dell_diags);
         else
-            snprintf(postcard_str, sizeof(postcard_str), "POST: %02X %02X", postcard_codes[0], postcard_prev_codes[0]);
+            snprintf(postcard_str, sizeof(postcard_str), "POST: %02X %02X%s", postcard_codes[0], postcard_prev_codes[0], dell_diags);
     }
 
     ui_sb_bugui(postcard_str);
@@ -224,9 +218,10 @@ postcard_init(UNUSED(const device_t *info))
         io_sethandler(postcard_port, postcard_ports_num,
                       NULL, NULL, NULL, postcard_write, NULL, NULL, NULL);
 
-    if (strstr(machines[machine].name, " Dell ") &&
-        (machine_get_chipset(machine) >= MACHINE_CHIPSET_INTEL_430FX))
-        io_sethandler(0x00e0, 0x0001,
+    postcard_dell_mode = strstr(machines[machine].name, " Dell ") &&
+                         (machine_get_chipset(machine) >= MACHINE_CHIPSET_INTEL_430FX);
+    if (postcard_dell_mode)
+        io_sethandler(is486 ? 0x00e0 : 0x00e4, 0x0001,
                       NULL, NULL, NULL, NULL, NULL, postcard_writel, NULL);
 
     return postcard_write;
diff --git a/src/include/86box/chipset.h b/src/include/86box/chipset.h
index 688a5fecb..e0e775fa1 100644
--- a/src/include/86box/chipset.h
+++ b/src/include/86box/chipset.h
@@ -55,6 +55,7 @@ extern const device_t neat_sx_device;
 extern const device_t scat_device;
 extern const device_t scat_4_device;
 extern const device_t scat_sx_device;
+extern const device_t cs8220_device;
 extern const device_t cs8230_device;
 extern const device_t cs4031_device;
 
@@ -112,6 +113,9 @@ extern const device_t slc90e66_device;
 
 extern const device_t ioapic_device;
 
+/* Olivetti */
+extern const device_t olivetti_eva_device;
+
 /* OPTi */
 extern const device_t opti283_device;
 extern const device_t opti291_device;
@@ -203,8 +207,4 @@ extern const device_t nec_mate_unk_device;
 
 extern const device_t phoenix_486_jumper_device;
 extern const device_t phoenix_486_jumper_pci_device;
-
-#ifdef USE_OLIVETTI
-extern const device_t olivetti_eva_device;
-#endif /* USE_OLIVETTI */
 #endif /*EMU_CHIPSET_H*/
diff --git a/src/include/86box/machine.h b/src/include/86box/machine.h
index 0dbbe98c5..3231acd80 100644
--- a/src/include/86box/machine.h
+++ b/src/include/86box/machine.h
@@ -211,6 +211,7 @@ enum {
     MACHINE_CHIPSET_SCAT_SX,
     MACHINE_CHIPSET_NEAT,
     MACHINE_CHIPSET_NEAT_SX,
+    MACHINE_CHIPSET_CT_AT,
     MACHINE_CHIPSET_CT_386,
     MACHINE_CHIPSET_CT_CS4031,
     MACHINE_CHIPSET_CONTAQ_82C596,
@@ -447,9 +448,6 @@ extern int machine_at_pb286_init(const machine_t *);
 extern int machine_at_siemens_init(const machine_t *); // Siemens PCD-2L. N82330 discrete machine. It segfaults in some places
 
 extern int machine_at_wellamerastar_init(const machine_t *); // Wells American A*Star with custom award BIOS 
-#ifdef USE_OPEN_AT
-extern int machine_at_openat_init(const machine_t *);
-#endif /* USE_OPEN_AT */
 
 /* m_at_286_386sx.c */
 extern int machine_at_tg286m_init(const machine_t *);
@@ -475,19 +473,19 @@ extern int machine_at_spc4216p_init(const machine_t *);
 extern int machine_at_spc4620p_init(const machine_t *);
 extern int machine_at_kmxc02_init(const machine_t *);
 extern int machine_at_deskmaster286_init(const machine_t *);
+extern int machine_at_dells200_init(const machine_t *);
 
 extern int machine_at_pc8_init(const machine_t *);
 extern int machine_at_3302_init(const machine_t *);
 
-#ifdef USE_OLIVETTI
 extern int machine_at_m290_init(const machine_t *);
-#endif /* USE_OLIVETTI */
 
 extern int machine_at_shuttle386sx_init(const machine_t *);
 extern int machine_at_adi386sx_init(const machine_t *);
 extern int machine_at_cmdsl386sx16_init(const machine_t *);
 extern int machine_at_cmdsl386sx25_init(const machine_t *);
 extern int machine_at_dataexpert386sx_init(const machine_t *);
+extern int machine_at_dells333sl_init(const machine_t *);
 extern int machine_at_if386sx_init(const machine_t *);
 extern int machine_at_spc6033p_init(const machine_t *);
 extern int machine_at_wd76c10_init(const machine_t *);
@@ -515,7 +513,7 @@ extern int machine_at_ga486l_init(const machine_t *);
 extern int machine_at_cougar_init(const machine_t *);
 
 extern int machine_at_acc386_init(const machine_t *);
-extern int machine_at_asus386_3364k_init(const machine_t *);
+extern int machine_at_asus3863364k_init(const machine_t *);
 extern int machine_at_asus386_init(const machine_t *);
 extern int machine_at_ecs386_init(const machine_t *);
 extern int machine_at_spc6000a_init(const machine_t *);
@@ -673,7 +671,7 @@ extern int machine_at_tek932_init(const machine_t *);
 
 extern int machine_at_acerv30_init(const machine_t *);
 extern int machine_at_apollo_init(const machine_t *);
-extern int machine_at_optiplex_gxl_init(const machine_t *);
+extern int machine_at_optiplexgxl_init(const machine_t *);
 extern int machine_at_zappa_init(const machine_t *);
 extern int machine_at_powermatev_init(const machine_t *);
 extern int machine_at_hawk_init(const machine_t *);
@@ -724,6 +722,8 @@ extern int machine_at_vectra54_init(const machine_t *);
 extern int machine_at_5sbm2_init(const machine_t *);
 
 /* m_at_socket7.c */
+extern void machine_at_optiplex_21152_init(void);
+
 extern int machine_at_acerv35n_init(const machine_t *);
 extern int machine_at_p55t2p4_init(const machine_t *);
 extern int machine_at_m7shi_init(const machine_t *);
@@ -753,12 +753,10 @@ extern int machine_at_gw2kte_init(const machine_t *);
 extern int machine_at_ma23c_init(const machine_t *);
 extern int machine_at_nupro592_init(const machine_t *);
 extern int machine_at_tx97_init(const machine_t *);
-extern int machine_at_optiplex_gn_init(const machine_t *);
-#ifdef USE_AN430TX
-extern int machine_at_an430tx_init(const machine_t *);
-#endif /* USE_AN430TX */
+extern int machine_at_optiplexgn_init(const machine_t *);
 extern int machine_at_ym430tx_init(const machine_t *);
 extern int machine_at_thunderbolt_init(const machine_t *);
+extern int machine_at_an430tx_init(const machine_t *);
 extern int machine_at_mb540n_init(const machine_t *);
 extern int machine_at_56a5_init(const machine_t *);
 extern int machine_at_p5mms98_init(const machine_t *);
@@ -824,7 +822,7 @@ extern int machine_at_p65up5_cpknd_init(const machine_t *);
 extern int machine_at_kn97_init(const machine_t *);
 
 extern int machine_at_lx6_init(const machine_t *);
-extern int machine_at_optiplex_gxa_init(const machine_t *);
+extern int machine_at_optiplexgxa_init(const machine_t *);
 extern int machine_at_spitfire_init(const machine_t *);
 extern int machine_at_ma30d_init(const machine_t *);
 
diff --git a/src/include/86box/pci.h b/src/include/86box/pci.h
index 462b4f821..8887f89f4 100644
--- a/src/include/86box/pci.h
+++ b/src/include/86box/pci.h
@@ -283,6 +283,7 @@ extern void        pci_init(int flags);
 
 /* PCI bridge stuff. */
 extern void        pci_bridge_set_ctl(void *priv, uint8_t ctl);
+extern uint8_t     pci_bridge_get_bus_index(void *priv);
 
 #ifdef EMU_DEVICE_H
 extern const device_t dec21150_device;
diff --git a/src/include/86box/snd_mmb.h b/src/include/86box/snd_mmb.h
new file mode 100644
index 000000000..6e5f7d3a8
--- /dev/null
+++ b/src/include/86box/snd_mmb.h
@@ -0,0 +1,42 @@
+/*
+ * 86Box    A hypervisor and IBM PC system emulator that specializes in
+ *          running old operating systems and software designed for IBM
+ *          PC systems and compatibles from 1981 through fairly recent
+ *          system designs based on the PCI bus.
+ *
+ *          This file is part of the 86Box distribution.
+ *
+ *          Mindscape Music Board emulation.
+ *
+ * Authors: Roy Baer, <https://pcem-emulator.co.uk/>
+ *          Jasmine Iwanek, <jriwanek@gmail.com>
+ *
+ *          Copyright 2025 Roy Baer.
+ *          Copyright 2025 Jasmine Iwanek.
+ */
+#ifndef _SOUND_SND_MMB_H_
+#define _SOUND_SND_MMB_H_
+
+#define MMB_FREQ FREQ_48000
+
+/* NOTE:
+ * The constant clock rate is a deviation from the real hardware which has
+ * the design flaw that the clock rate is always half the ISA bus clock.
+ */
+#define MMB_CLOCK 2386364
+
+typedef struct ay_3_891x_s {
+    uint8_t index;
+    uint8_t regs[16];
+    struct  ayumi chip;
+} ay_3_891x_t;
+
+typedef struct mmb_s {
+    ay_3_891x_t first;
+    ay_3_891x_t second;
+
+    int16_t buffer[SOUNDBUFLEN * 2];
+    int     pos;
+} mmb_t;
+
+#endif /* _SOUND_SND_MMB_H_ */
diff --git a/src/include/86box/sound.h b/src/include/86box/sound.h
index a30095c66..985abe777 100644
--- a/src/include/86box/sound.h
+++ b/src/include/86box/sound.h
@@ -197,6 +197,7 @@ extern const device_t ct5880_onboard_device;
 
 /* Gravis UltraSound and UltraSound Max */
 extern const device_t gus_device;
+extern const device_t gus_max_device;
 
 /* IBM PS/1 Audio Card */
 extern const device_t ps1snd_device;
@@ -205,6 +206,9 @@ extern const device_t ps1snd_device;
 extern const device_t ssi2001_device;
 extern const device_t entertainer_device;
 
+/* Mindscape Music Board */
+extern const device_t mmb_device;
+
 /* Pro Audio Spectrum Plus, 16, and 16D */
 extern const device_t pasplus_device;
 extern const device_t pas16_device;
diff --git a/src/include/86box/video.h b/src/include/86box/video.h
index fbdb9f49e..8cd672a63 100644
--- a/src/include/86box/video.h
+++ b/src/include/86box/video.h
@@ -36,6 +36,10 @@ using atomic_int  = std::atomic_int;
 #define getcolg(color) (((color) >> 8) & 0xFF)
 #define getcolb(color) ((color) & 0xFF)
 
+#ifdef __cplusplus
+extern "C" {
+#endif
+
 enum {
     VID_NONE = 0,
     VID_INTERNAL
@@ -49,10 +53,6 @@ enum {
     FULLSCR_SCALE_INT43
 };
 
-#ifdef __cplusplus
-extern "C" {
-#endif
-
 enum {
     VIDEO_ISA = 0,
     VIDEO_MCA,
@@ -71,6 +71,11 @@ enum {
 
 #define VIDEO_FLAG_TYPE_SECONDARY VIDEO_FLAG_TYPE_SPECIAL
 
+#define FONT_IBM_MDA_437_PATH        "roms/video/mda/mda.rom"
+#define FONT_IBM_MDA_437_NORDIC_PATH "roms/video/mda/4733197.bin"
+#define FONT_KAM_PATH                "roms/video/mda/kam.bin"
+#define FONT_KAMCL16_PATH            "roms/video/mda/kamcl16.bin"
+
 typedef struct video_timings_t {
     int type;
     int write_b;
@@ -189,15 +194,15 @@ extern uint32_t     pal_lookup[256];
 #endif
 extern int          video_fullscreen;
 extern int          video_fullscreen_scale;
-extern uint8_t      fontdat[2048][8];
-extern uint8_t      fontdatm[2048][16];
-extern uint8_t      fontdat2[2048][8];
-extern uint8_t      fontdatm2[2048][16];
-extern uint8_t      fontdatw[512][32];
-extern uint8_t      fontdat8x12[256][16];
-extern uint8_t      fontdat12x18[256][36];
-extern dbcs_font_t *fontdatksc5601;
-extern dbcs_font_t *fontdatksc5601_user;
+extern uint8_t      fontdat[2048][8];      /* IBM CGA font */
+extern uint8_t      fontdatm[2048][16];    /* IBM MDA font */
+extern uint8_t      fontdat2[2048][8];     /* IBM CGA 2nd instance font */
+extern uint8_t      fontdatm2[2048][16];   /* IBM MDA 2nd instance font */
+extern uint8_t      fontdatw[512][32];     /* Wyse700 font */
+extern uint8_t      fontdat8x12[256][16];  /* MDSI Genius font */
+extern uint8_t      fontdat12x18[256][36]; /* IM1024 font */
+extern dbcs_font_t *fontdatksc5601;        /* Korean KSC-5601 font */
+extern dbcs_font_t *fontdatksc5601_user;   /* Korean KSC-5601 user defined font */
 extern uint32_t    *video_6to8;
 extern uint32_t    *video_8togs;
 extern uint32_t    *video_8to32;
@@ -277,8 +282,8 @@ extern uint8_t video_force_resize_get_monitor(int monitor_index);
 extern void    video_force_resize_set_monitor(uint8_t res, int monitor_index);
 extern void    video_update_timing(void);
 
-extern void loadfont_ex(char *s, int format, int offset);
-extern void loadfont(char *s, int format);
+extern void loadfont_ex(char *fn, int format, int offset);
+extern void loadfont(char *fn, int format);
 
 extern int get_actual_size_x(void);
 extern int get_actual_size_y(void);
@@ -351,6 +356,7 @@ extern const device_t gd5401_isa_device;
 extern const device_t gd5402_isa_device;
 extern const device_t gd5402_onboard_device;
 extern const device_t gd5420_isa_device;
+extern const device_t gd5420_onboard_device;
 extern const device_t gd5422_isa_device;
 extern const device_t gd5424_vlb_device;
 extern const device_t gd5426_isa_device;
diff --git a/src/machine/CMakeLists.txt b/src/machine/CMakeLists.txt
index 4098f2553..8cd54edec 100644
--- a/src/machine/CMakeLists.txt
+++ b/src/machine/CMakeLists.txt
@@ -56,19 +56,3 @@ add_library(mch OBJECT
     m_at_socket370.c
     m_at_misc.c
 )
-
-if(AN430TX)
-    target_compile_definitions(mch PRIVATE USE_AN430TX)
-endif()
-
-if(DESKPRO386)
-    target_compile_definitions(mch PRIVATE USE_DESKPRO386)
-endif()
-
-if(OLIVETTI)
-    target_compile_definitions(mch PRIVATE USE_OLIVETTI)
-endif()
-
-if(OPEN_AT)
-    target_compile_definitions(mch PRIVATE USE_OPEN_AT)
-endif()
diff --git a/src/machine/m_amstrad.c b/src/machine/m_amstrad.c
index 3dba578bd..814d95ffd 100644
--- a/src/machine/m_amstrad.c
+++ b/src/machine/m_amstrad.c
@@ -2936,7 +2936,7 @@ machine_amstrad_init(const machine_t *model, int type)
                 break;
 
             case AMS_PC1640:
-                loadfont("roms/video/mda/mda.rom", 0);
+                loadfont(FONT_IBM_MDA_437_PATH, 0);
                 device_context(&vid_1640_device);
                 ams->language = device_get_config_int("language");
                 vid_init_1640(ams);
diff --git a/src/machine/m_at.c b/src/machine/m_at.c
index 86fbe3776..13cd831ba 100644
--- a/src/machine/m_at.c
+++ b/src/machine/m_at.c
@@ -388,21 +388,3 @@ machine_at_wellamerastar_init(const machine_t *model)
 
     return ret;
 }
-
-#ifdef USE_OPEN_AT
-int
-machine_at_openat_init(const machine_t *model)
-{
-    int ret;
-
-    ret = bios_load_linear("roms/machines/openat/bios.bin",
-                           0x000f0000, 65536, 0);
-
-    if (bios_only || !ret)
-        return ret;
-
-    machine_at_ibm_common_init(model);
-
-    return ret;
-}
-#endif /* USE_OPEN_AT */
diff --git a/src/machine/m_at_286_386sx.c b/src/machine/m_at_286_386sx.c
index e7aa66662..6ac5b0195 100644
--- a/src/machine/m_at_286_386sx.c
+++ b/src/machine/m_at_286_386sx.c
@@ -37,6 +37,7 @@
 #include <86box/hdc.h>
 #include <86box/nvr.h>
 #include <86box/port_6x.h>
+#define USE_SIO_DETECT
 #include <86box/sio.h>
 #include <86box/serial.h>
 #include <86box/video.h>
@@ -261,6 +262,30 @@ machine_at_px286_init(const machine_t *model)
     return ret;
 }
 
+int
+machine_at_dells200_init(const machine_t *model)
+{
+    int ret;
+
+    ret = bios_load_interleaved("roms/machines/dells200/dellL200256_LO_@DIP28.BIN",
+                                "roms/machines/dells200/Dell200256_HI_@DIP28.BIN",
+                                0x000f0000, 65536, 0);
+
+    if (bios_only || !ret)
+        return ret;
+
+    machine_at_common_init(model);
+
+    device_add(&cs8220_device);
+
+    if (fdc_current[0] == FDC_INTERNAL)
+        device_add(&fdc_at_device);
+
+    device_add(&keyboard_at_phoenix_device);
+
+    return ret;
+}
+
 int
 machine_at_micronics386_init(const machine_t *model)
 {
@@ -736,6 +761,75 @@ machine_at_cmdsl386sx25_init(const machine_t *model)
     return ret;
 }
 
+static const device_config_t dells333sl_config[] = {
+    // clang-format off
+    {
+        .name = "bios",
+        .description = "BIOS Version",
+        .type = CONFIG_BIOS,
+        .default_string = "dells333sl",
+        .default_int = 0,
+        .file_filter = "",
+        .spinner = { 0 },
+        .bios = {
+            { .name = "J01 (Jostens Learning Corporation OEM)", .internal_name = "dells333sl_j01", .bios_type = BIOS_NORMAL, 
+              .files_no = 1, .local = 0, .size = 131072, .files = { "roms/machines/dells333sl/DELL386.BIN", "" } },
+            { .name = "A02", .internal_name = "dells333sl", .bios_type = BIOS_NORMAL, 
+              .files_no = 1, .local = 0, .size = 131072, .files = { "roms/machines/dells333sl/Dell_386SX_30807_UBIOS_B400_VLSI_VL82C311_Cirrus_Logic_GD5420.bin", "" } },
+            { .files_no = 0 }
+        },
+    },
+    { .name = "", .description = "", .type = CONFIG_END }
+    // clang-format on
+};
+
+const device_t dells333sl_device = {
+    .name          = "Dell System 333s/L",
+    .internal_name = "dells333sl_device",
+    .flags         = 0,
+    .local         = 0,
+    .init          = NULL,
+    .close         = NULL,
+    .reset         = NULL,
+    .available     = NULL,
+    .speed_changed = NULL,
+    .force_redraw  = NULL,
+    .config        = dells333sl_config
+};
+
+int
+machine_at_dells333sl_init(const machine_t *model)
+{
+    int ret = 0;
+    const char* fn;
+
+    /* No ROMs available */
+    if (!device_available(model->device))
+        return ret;
+
+    device_context(model->device);
+    fn = device_get_bios_file(machine_get_device(machine), device_get_config_bios("bios"), 0);
+    ret = bios_load_linear(fn, 0x000e0000, 262144, 0);
+    memcpy(rom, &(rom[0x00020000]), 131072);
+    mem_mapping_set_addr(&bios_mapping, 0x0c0000, 0x40000);
+    mem_mapping_set_exec(&bios_mapping, rom);
+    device_context_restore();
+
+    if (gfxcard[0] == VID_INTERNAL)
+        device_add(machine_get_vid_device(machine));
+
+    machine_at_common_init_ex(model, 2);
+
+    device_add(&ide_isa_device);
+
+    device_add(&pc87311_device);
+    device_add(&vl82c113_device); /* The keyboard controller is part of the VL82c113. */
+
+    device_add(&vlsi_scamp_device);
+
+    return ret;
+}
+
 int
 machine_at_dataexpert386sx_init(const machine_t *model)
 {
@@ -1045,7 +1139,6 @@ machine_at_pc916sx_init(const machine_t *model)
     return ret;
 }
 
-#ifdef USE_OLIVETTI
 int
 machine_at_m290_init(const machine_t *model)
 {
@@ -1057,15 +1150,16 @@ machine_at_m290_init(const machine_t *model)
     if (bios_only || !ret)
         return ret;
 
-    machine_at_common_init_ex(model, 4);
-    device_add(&keyboard_at_olivetti_device);
+    machine_at_common_init_ex(model, 6);
+    device_add(&amstrad_megapc_nvr_device);
+
+    device_add(&olivetti_eva_device);
     device_add(&port_6x_olivetti_device);
 
     if (fdc_current[0] == FDC_INTERNAL)
         device_add(&fdc_at_device);
 
-    device_add(&olivetti_eva_device);
+    device_add(&keyboard_at_olivetti_device);
 
     return ret;
 }
-#endif /* USE_OLIVETTI */
diff --git a/src/machine/m_at_386dx_486.c b/src/machine/m_at_386dx_486.c
index 9f7534244..b81a6bda7 100644
--- a/src/machine/m_at_386dx_486.c
+++ b/src/machine/m_at_386dx_486.c
@@ -73,11 +73,11 @@ machine_at_acc386_init(const machine_t *model)
 }
 
 int
-machine_at_asus386_3364k_init(const machine_t *model)
+machine_at_asus3863364k_init(const machine_t *model)
 {
     int ret;
 
-    ret = bios_load_linear("roms/machines/asus386_3364k/am27c512dip28-64b53c26be3d8160533563.bin",
+    ret = bios_load_linear("roms/machines/asus3863364k/am27c512dip28-64b53c26be3d8160533563.bin",
                            0x000f0000, 65536, 0);
 
     if (bios_only || !ret)
diff --git a/src/machine/m_at_slot1.c b/src/machine/m_at_slot1.c
index a147d0e13..2ac805bee 100644
--- a/src/machine/m_at_slot1.c
+++ b/src/machine/m_at_slot1.c
@@ -151,11 +151,11 @@ machine_at_lx6_init(const machine_t *model)
 }
 
 int
-machine_at_optiplex_gxa_init(const machine_t *model)
+machine_at_optiplexgxa_init(const machine_t *model)
 {
     int ret;
 
-    ret = bios_load_linear("roms/machines/optiplex_gxa/DELL.ROM",
+    ret = bios_load_linear("roms/machines/optiplexgxa/DELL.ROM",
                            0x000c0000, 262144, 0);
 
     if (bios_only || !ret)
@@ -170,14 +170,14 @@ machine_at_optiplex_gxa_init(const machine_t *model)
     pci_register_slot(0x11, PCI_CARD_NETWORK,     4, 0, 0, 0);
     pci_register_slot(0x0E, PCI_CARD_NORMAL,      3, 4, 2, 1);
     pci_register_slot(0x0D, PCI_CARD_NORMAL,      2, 1, 3, 4);
-    pci_register_slot(0x0F, PCI_CARD_BRIDGE,      1, 2, 3, 4);
+    pci_register_slot(0x0F, PCI_CARD_BRIDGE,      0, 0, 0, 0);
 
     if (sound_card_current[0] == SOUND_INTERNAL)
         device_add(machine_get_snd_device(machine));
 
     device_add(&i440lx_device);
     device_add(&piix4_device);
-    device_add(&dec21152_device);
+    machine_at_optiplex_21152_init();
     device_add_params(&pc87307_device, (void *) (PCX730X_PHOENIX_42 | PCX7307_PC87307));
     device_add(&intel_flash_bxt_device);
     spd_register(SPD_TYPE_SDRAM, 0x7, 256);
diff --git a/src/machine/m_at_socket5.c b/src/machine/m_at_socket5.c
index 442281811..0d50fead8 100644
--- a/src/machine/m_at_socket5.c
+++ b/src/machine/m_at_socket5.c
@@ -238,11 +238,11 @@ machine_at_apollo_init(const machine_t *model)
 }
 
 int
-machine_at_optiplex_gxl_init(const machine_t *model)
+machine_at_optiplexgxl_init(const machine_t *model)
 {
     int ret;
 
-    ret = bios_load_linear("roms/machines/optiplex_gxl/DELL.ROM",
+    ret = bios_load_linear("roms/machines/optiplexgxl/DELL.ROM",
                            0x000e0000, 131072, 0);
 
     if (bios_only || !ret)
diff --git a/src/machine/m_at_socket7.c b/src/machine/m_at_socket7.c
index 7d2441e18..46c7b7623 100644
--- a/src/machine/m_at_socket7.c
+++ b/src/machine/m_at_socket7.c
@@ -46,6 +46,15 @@
 #include <86box/network.h>
 #include <86box/pci.h>
 
+void
+machine_at_optiplex_21152_init(void)
+{
+    uint8_t bus_index = pci_bridge_get_bus_index(device_add(&dec21152_device));
+    pci_register_bus_slot(bus_index, 0x09, PCI_CARD_NORMAL, 1, 2, 3, 4);
+    pci_register_bus_slot(bus_index, 0x0a, PCI_CARD_NORMAL, 4, 2, 1, 3);
+    pci_register_bus_slot(bus_index, 0x0b, PCI_CARD_NORMAL, 1, 3, 4, 2);
+}
+
 int
 machine_at_acerv35n_init(const machine_t *model)
 {
@@ -970,11 +979,11 @@ machine_at_tx97_init(const machine_t *model)
 }
 
 int
-machine_at_optiplex_gn_init(const machine_t *model)
+machine_at_optiplexgn_init(const machine_t *model)
 {
     int ret;
 
-    ret = bios_load_linear("roms/machines/optiplex_gn/DELL.ROM",
+    ret = bios_load_linear("roms/machines/optiplexgn/DELL.ROM",
                            0x000c0000, 262144, 0);
 
     if (bios_only || !ret)
@@ -989,7 +998,7 @@ machine_at_optiplex_gn_init(const machine_t *model)
     pci_register_slot(0x10, PCI_CARD_VIDEO,       4, 0, 0, 0); /* Trio64V2/GX, temporarily Trio64V2/DX is given */
     pci_register_slot(0x11, PCI_CARD_NETWORK,     4, 0, 0, 0); /* 3C905, not yet emulated */
     pci_register_slot(0x07, PCI_CARD_SOUTHBRIDGE, 0, 0, 0, 4);
-    pci_register_slot(0x0F, PCI_CARD_BRIDGE,      1, 2, 3, 4);
+    pci_register_slot(0x0F, PCI_CARD_BRIDGE,      0, 0, 0, 0);
 
     if (gfxcard[0] == VID_INTERNAL)
         device_add(machine_get_vid_device(machine));
@@ -999,7 +1008,7 @@ machine_at_optiplex_gn_init(const machine_t *model)
 
     device_add(&i430tx_device);
     device_add(&piix4_device);
-    device_add(&dec21152_device);
+    machine_at_optiplex_21152_init();
     device_add_params(&pc87307_device, (void *) (PCX730X_PHOENIX_42 | PCX7307_PC87307));
     device_add(&intel_flash_bxt_device);
     spd_register(SPD_TYPE_SDRAM, 0x3, 128);
@@ -1007,27 +1016,17 @@ machine_at_optiplex_gn_init(const machine_t *model)
     return ret;
 }
 
-#ifdef USE_AN430TX
 int
 machine_at_an430tx_init(const machine_t *model)
 {
     int ret;
 
-#    if 1
-    ret = bios_load_linear_combined2("roms/machines/an430tx/P10-0095.BIO",
-                                     "roms/machines/an430tx/P10-0095.BI1",
-                                     "roms/machines/an430tx/P10-0095.BI2",
-                                     "roms/machines/an430tx/P10-0095.BI3",
-                                     "roms/machines/an430tx/P10-0095.RCV",
+    ret = bios_load_linear_combined2("roms/machines/an430tx/ANP0911A.BIO",
+                                     "roms/machines/an430tx/ANP0911A.BI1",
+                                     "roms/machines/an430tx/ANP0911A.BI2",
+                                     "roms/machines/an430tx/ANP0911A.BI3",
+                                     "roms/machines/an430tx/ANP0911A.RCV",
                                      0x3a000, 160);
-#    else
-    ret = bios_load_linear_combined2("roms/machines/an430tx/P06-0062.BIO",
-                                     "roms/machines/an430tx/P06-0062.BI1",
-                                     "roms/machines/an430tx/P06-0062.BI2",
-                                     "roms/machines/an430tx/P06-0062.BI3",
-                                     "roms/machines/an430tx/P10-0095.RCV",
-                                     0x3a000, 160);
-#    endif
 
     if (bios_only || !ret)
         return ret;
@@ -1036,21 +1035,25 @@ machine_at_an430tx_init(const machine_t *model)
 
     pci_init(PCI_CONFIG_TYPE_1);
     pci_register_slot(0x00, PCI_CARD_NORTHBRIDGE, 0, 0, 0, 0);
-    pci_register_slot(0x07, PCI_CARD_SOUTHBRIDGE, 1, 2, 3, 4); /* PIIX4 */
-    // pci_register_slot(0x08, PCI_CARD_VIDEO,       4, 0, 0, 0);
+    pci_register_slot(0x07, PCI_CARD_SOUTHBRIDGE, 0, 0, 0, 4); /* PIIX4 */
     pci_register_slot(0x0D, PCI_CARD_NORMAL,      1, 2, 3, 4);
     pci_register_slot(0x0E, PCI_CARD_NORMAL,      2, 3, 4, 1);
     pci_register_slot(0x0F, PCI_CARD_NORMAL,      3, 4, 1, 2);
     pci_register_slot(0x10, PCI_CARD_NORMAL,      4, 1, 2, 3);
+    pci_register_slot(0x08, PCI_CARD_VIDEO,       4, 0, 0, 0);
     device_add(&i430tx_device);
     device_add(&piix4_device);
+#ifdef FOLLOW_THE_SPECIFICATION
     device_add_params(&pc87307_device, (void *) (PCX730X_PHOENIX_42I | PCX7307_PC97307));
+#else
+    /* The technical specification says Phoenix, a real machnine HWINFO dump says AMI '5'. */
+    device_add_params(&pc87307_device, (void *) (PCX730X_AMI | PCX7307_PC97307));
+#endif
     device_add(&intel_flash_bxt_ami_device);
     spd_register(SPD_TYPE_SDRAM, 0x3, 128);
 
     return ret;
 }
-#endif /* USE_AN430TX */
 
 int
 machine_at_ym430tx_init(const machine_t *model)
diff --git a/src/machine/m_pcjr.c b/src/machine/m_pcjr.c
index d4d3b09cf..cb69bd9e5 100644
--- a/src/machine/m_pcjr.c
+++ b/src/machine/m_pcjr.c
@@ -1541,7 +1541,7 @@ machine_pcjr_init(UNUSED(const machine_t *model))
 
     /* Initialize the video controller. */
     video_reset(gfxcard[0]);
-    loadfont("roms/video/mda/mda.rom", 0);
+    loadfont(FONT_IBM_MDA_437_PATH, 0);
     device_context(&pcjr_device);
     pcjr_vid_init(pcjr);
     device_context_restore();
diff --git a/src/machine/machine_table.c b/src/machine/machine_table.c
index a3a02bfcd..5626b0728 100644
--- a/src/machine/machine_table.c
+++ b/src/machine/machine_table.c
@@ -8,17 +8,12 @@
  *
  *          Handling of the emulated machines.
  *
- * NOTES:   OpenAT wip for 286-class machine with open BIOS.
- *          PS2_M80-486 wip, pending receipt of TRM's for machine.
- *
- *
- *
  * Authors: Miran Grca, <mgrca8@gmail.com>
  *          Fred N. van Kempen, <decwiz@yahoo.com>
  *          Jasmine Iwanek, <jriwanek@gmail.com>
  *
- *          Copyright 2016-2020 Miran Grca.
- *          Copyright 2017-2020 Fred N. van Kempen.
+ *          Copyright 2016-2025 Miran Grca.
+ *          Copyright 2017-2025 Fred N. van Kempen.
  *          Copyright 2025      Jasmine Iwanek.
  */
 #include <stdio.h>
@@ -71,6 +66,7 @@ extern const device_t vendex_device;
 extern const device_t c5sbm2_device;
 extern const device_t sb486pv_device;
 extern const device_t ap5s_device;
+extern const device_t dells333sl_device;
 
 const machine_filter_t machine_types[] = {
     { "None",                             MACHINE_TYPE_NONE       },
@@ -117,11 +113,12 @@ const machine_filter_t machine_chipsets[] = {
     { "ALi ALADDiN IV+",            MACHINE_CHIPSET_ALI_ALADDIN_IV_PLUS },
     { "ALi ALADDiN V",              MACHINE_CHIPSET_ALI_ALADDIN_V       },
     { "ALi ALADDiN-PRO II",         MACHINE_CHIPSET_ALI_ALADDIN_PRO_II  },
+    { "C&T PC/AT",                  MACHINE_CHIPSET_CT_AT               },
+    { "C&T 386/AT",                 MACHINE_CHIPSET_CT_386              },
     { "C&T 82C235 SCAT",            MACHINE_CHIPSET_SCAT                },
     { "C&T 82C236 SCATsx",          MACHINE_CHIPSET_SCAT_SX             },
     { "C&T CS8221 NEAT",            MACHINE_CHIPSET_NEAT                },
     { "C&T CS8281 NEATsx",          MACHINE_CHIPSET_NEAT_SX             },
-    { "C&T 386",                    MACHINE_CHIPSET_CT_386              },
     { "C&T CS4031",                 MACHINE_CHIPSET_CT_CS4031           },
     { "Contaq 82C596",              MACHINE_CHIPSET_CONTAQ_82C596       },
     { "Contaq 82C597",              MACHINE_CHIPSET_CONTAQ_82C597       },
@@ -3095,7 +3092,6 @@ const machine_t machines[] = {
         .snd_device = NULL,
         .net_device = NULL
     },
-#ifdef USE_OLIVETTI
     /* Has Olivetti KBC firmware. */
     {
         .name = "[ISA] Olivetti M290",
@@ -3136,49 +3132,6 @@ const machine_t machines[] = {
         .snd_device = NULL,
         .net_device = NULL
     },
-#endif /* USE_OLIVETTI */
-#ifdef USE_OPEN_AT
-    /* Has IBM AT KBC firmware. */
-    {
-        .name = "[ISA] OpenAT",
-        .internal_name = "openat",
-        .type = MACHINE_TYPE_286,
-        .chipset = MACHINE_CHIPSET_DISCRETE,
-        .init = machine_at_openat_init,
-        .p1_handler = NULL,
-        .gpio_handler = NULL,
-        .available_flag = MACHINE_AVAILABLE,
-        .gpio_acpi_handler = NULL,
-        .cpu = {
-            .package = CPU_PKG_286,
-            .block = CPU_BLOCK_NONE,
-            .min_bus = 0,
-            .max_bus = 0,
-            .min_voltage = 0,
-            .max_voltage = 0,
-            .min_multi = 0,
-            .max_multi = 0
-        },
-        .bus_flags = MACHINE_AT,
-        .flags = MACHINE_FLAGS_NONE,
-        .ram = {
-            .min = 256,
-            .max = 15872,
-            .step = 128
-        },
-        .nvrmask = 63,
-        .kbc_device = NULL,
-        .kbc_p1 = 0xff,
-        .gpio = 0xffffffff,
-        .gpio_acpi = 0xffffffff,
-        .device = NULL,
-        .fdc_device = NULL,
-        .sio_device = NULL,
-        .vid_device = NULL,
-        .snd_device = NULL,
-        .net_device = NULL
-    },
-#endif /* USE_OPEN_AT */
     /* Has IBM AT KBC firmware. */
     {
         .name = "[ISA] Phoenix IBM AT",
@@ -3419,6 +3372,47 @@ const machine_t machines[] = {
         .snd_device = NULL,
         .net_device = NULL
     },
+    /* No proper pictures of the KBC exist, though it seems to have the IBM AT KBC
+       firmware. */
+    {
+        .name = "[C&T PC/AT] Dell System 200",
+        .internal_name = "dells200",
+        .type = MACHINE_TYPE_286,
+        .chipset = MACHINE_CHIPSET_CT_AT,
+        .init = machine_at_dells200_init,
+        .p1_handler = NULL,
+        .gpio_handler = NULL,
+        .available_flag = MACHINE_AVAILABLE,
+        .gpio_acpi_handler = NULL,
+        .cpu = {
+            .package = CPU_PKG_286,
+            .block = CPU_BLOCK_NONE,
+            .min_bus = 6000000,
+            .max_bus = 12000000,
+            .min_voltage = 0,
+            .max_voltage = 0,
+            .min_multi = 0,
+            .max_multi = 0
+        },
+        .bus_flags = MACHINE_AT,
+        .flags = MACHINE_FLAGS_NONE,
+        .ram = {
+            .min = 640,
+            .max = 16384,
+            .step = 128
+        },
+        .nvrmask = 127,
+        .kbc_device = NULL,
+        .kbc_p1 = 0xff,
+        .gpio = 0xffffffff,
+        .gpio_acpi = 0xffffffff,
+        .device = NULL,
+        .fdc_device = NULL,
+        .sio_device = NULL,
+        .vid_device = NULL,
+        .snd_device = NULL,
+        .net_device = NULL
+    },
     /* Has Quadtel KBC firmware. */
     {
         .name = "[GC103] Quadtel 286 clone",
@@ -4463,7 +4457,7 @@ const machine_t machines[] = {
         .net_device = NULL
     },
             {
-        .name = "[ALI M1409] Acer 100T",
+        .name = "[ALi M1409] Acer 100T",
         .internal_name = "acer100t",
         .type = MACHINE_TYPE_386SX,
         .chipset = MACHINE_CHIPSET_ALI_M1409,
@@ -4949,6 +4943,47 @@ const machine_t machines[] = {
         .snd_device = NULL,
         .net_device = NULL
     },
+    /* No proper pictures of the KBC exist, though it seems to have the IBM AT KBC
+       firmware. */
+    {
+        .name = "[SCAMP] Dell System 333s/L",
+        .internal_name = "dells333sl",
+        .type = MACHINE_TYPE_386SX,
+        .chipset = MACHINE_CHIPSET_VLSI_SCAMP,
+        .init = machine_at_dells333sl_init,
+        .p1_handler = NULL,
+        .gpio_handler = NULL,
+        .available_flag = MACHINE_AVAILABLE,
+        .gpio_acpi_handler = NULL,
+        .cpu = {
+            .package = CPU_PKG_386SX,
+            .block = CPU_BLOCK_NONE,
+            .min_bus = 10000000,
+            .max_bus = 33333333,
+            .min_voltage = 0,
+            .max_voltage = 0,
+            .min_multi = 0,
+            .max_multi = 0
+        },
+        .bus_flags = MACHINE_PS2,
+        .flags = MACHINE_IDE | MACHINE_VIDEO,
+        .ram = {
+            .min = 1024,
+            .max = 16384,
+            .step = 128
+        },
+        .nvrmask = 127,
+        .kbc_device = NULL,
+        .kbc_p1 = 0xff,
+        .gpio = 0xffffffff,
+        .gpio_acpi = 0xffffffff,
+        .device = &dells333sl_device,
+        .fdc_device = NULL,
+        .sio_device = NULL,
+        .vid_device = &gd5420_onboard_device,
+        .snd_device = NULL,
+        .net_device = NULL
+    },
     /* Has IBM PS/2 Type 1 KBC firmware. */
     {
         .name = "[SCAMP] Samsung SPC-6033P",
@@ -5239,7 +5274,7 @@ const machine_t machines[] = {
     },
     /* Has an AMI Keyboard BIOS PLUS KBC firmware ('8'). */
     {
-        .name = "[C&T 386] ECS 386/32",
+        .name = "[C&T 386/AT] ECS 386/32",
         .internal_name = "ecs386",
         .type = MACHINE_TYPE_386DX,
         .chipset = MACHINE_CHIPSET_CT_386,
@@ -5279,7 +5314,7 @@ const machine_t machines[] = {
     },
     /* Has IBM AT KBC firmware. */
     {
-        .name = "[C&T 386] Samsung SPC-6000A",
+        .name = "[C&T 386/AT] Samsung SPC-6000A",
         .internal_name = "spc6000a",
         .type = MACHINE_TYPE_386DX,
         .chipset = MACHINE_CHIPSET_CT_386,
@@ -5678,10 +5713,10 @@ const machine_t machines[] = {
     /* Has Award KBC firmware. */
     {
         .name = "[SiS 310] ASUS 386/33-64K",
-        .internal_name = "asus386_3364k",
+        .internal_name = "asus3863364k",
         .type = MACHINE_TYPE_386DX,
         .chipset = MACHINE_CHIPSET_SIS_310,
-        .init = machine_at_asus386_3364k_init,
+        .init = machine_at_asus3863364k_init,
         .p1_handler = NULL,
         .gpio_handler = NULL,
         .available_flag = MACHINE_AVAILABLE,
@@ -9429,7 +9464,7 @@ const machine_t machines[] = {
             .max_multi = 2.0
         },
         .bus_flags = MACHINE_PS2_PCI,
-        .flags = MACHINE_IDE_DUAL | MACHINE_APM, /* Machine has internal video: ST STPC Atlas */
+        .flags = MACHINE_IDE_DUAL | MACHINE_APM | MACHINE_PCI_INTERNAL, /* Machine has internal video: ST STPC Atlas */
         .ram = {
             .min = 32768,
             .max = 163840,
@@ -9470,7 +9505,7 @@ const machine_t machines[] = {
             .max_multi = 2.0
         },
         .bus_flags = MACHINE_PS2_PCI | MACHINE_BUS_USB,
-        .flags = MACHINE_IDE_DUAL | MACHINE_APM | MACHINE_USB, /* Machine has internal video: ST STPC Atlas */
+        .flags = MACHINE_IDE_DUAL | MACHINE_APM | MACHINE_PCI_INTERNAL | MACHINE_USB, /* Machine has internal video: ST STPC Atlas */
         .ram = {
             .min = 32768,
             .max = 163840,
@@ -9511,7 +9546,7 @@ const machine_t machines[] = {
             .max_multi = 2.0
         },
         .bus_flags = MACHINE_PS2,
-        .flags = MACHINE_IDE | MACHINE_APM, /* Machine has internal video: ST STPC Atlas and NIC: Realtek RTL8139C+ */
+        .flags = MACHINE_IDE | MACHINE_APM | MACHINE_PCI_INTERNAL, /* Machine has internal video: ST STPC Atlas and NIC: Realtek RTL8139C+ */
         .ram = {
             .min = 32768,
             .max = 131072,
@@ -9552,7 +9587,7 @@ const machine_t machines[] = {
             .max_multi = 2.0
         },
         .bus_flags = MACHINE_PS2_PCI,
-        .flags = MACHINE_IDE_DUAL | MACHINE_APM,
+        .flags = MACHINE_IDE_DUAL | MACHINE_APM | MACHINE_PCI_INTERNAL,
         .ram = {
             .min = 32768,
             .max = 98304,
@@ -9593,7 +9628,7 @@ const machine_t machines[] = {
             .max_multi = 2.0
         },
         .bus_flags = MACHINE_PS2_PCI,
-        .flags = MACHINE_IDE_DUAL | MACHINE_APM,
+        .flags = MACHINE_IDE_DUAL | MACHINE_APM | MACHINE_PCI_INTERNAL,
         .ram = {
             .min = 32768,
             .max = 131072,
@@ -10556,10 +10591,10 @@ const machine_t machines[] = {
     /* Has a National Semiconductor PC87332VLJ Super I/O with AMIKey 'F' KBC firmware. */
     {
         .name = "[i430FX] Dell OptiPlex GXL/GXM",
-        .internal_name = "optiplex_gxl",
+        .internal_name = "optiplexgxl",
         .type = MACHINE_TYPE_SOCKET5,
         .chipset = MACHINE_CHIPSET_INTEL_430FX,
-        .init = machine_at_optiplex_gxl_init,
+        .init = machine_at_optiplexgxl_init,
         .p1_handler = NULL,
         .gpio_handler = NULL,
         .available_flag = MACHINE_AVAILABLE,
@@ -13154,10 +13189,10 @@ const machine_t machines[] = {
      */
     {
         .name = "[i430TX] Dell OptiPlex GN+",
-        .internal_name = "optiplex_gn",
+        .internal_name = "optiplexgn",
         .type = MACHINE_TYPE_SOCKET7,
         .chipset = MACHINE_CHIPSET_INTEL_430TX,
-        .init = machine_at_optiplex_gn_init,
+        .init = machine_at_optiplexgn_init,
         .p1_handler = NULL,
         .gpio_handler = NULL,
         .available_flag = MACHINE_AVAILABLE,
@@ -13233,49 +13268,6 @@ const machine_t machines[] = {
         .snd_device = &cs4236b_device,
         .net_device = &pcnet_am79c973_onboard_device
     },
-#ifdef USE_AN430TX
-    /* This has the Phoenix MultiKey KBC firmware. */
-    {
-        .name = "[i430TX] Intel AN430TX (Anchorage)",
-        .internal_name = "an430tx",
-        .type = MACHINE_TYPE_SOCKET7,
-        .chipset = MACHINE_CHIPSET_INTEL_430TX,
-        .init = machine_at_an430tx_init,
-        .p1_handler = NULL,
-        .gpio_handler = NULL,
-        .available_flag = MACHINE_AVAILABLE,
-        .gpio_acpi_handler = NULL,
-        .cpu = {
-            .package = CPU_PKG_SOCKET5_7,
-            .block = CPU_BLOCK(CPU_K5, CPU_5K86, CPU_K6, CPU_K6_2, CPU_K6_2C, CPU_K6_3, CPU_K6_2P,
-                               CPU_K6_3P, CPU_Cx6x86, CPU_Cx6x86MX, CPU_Cx6x86L),
-            .min_bus = 60000000,
-            .max_bus = 66666667,
-            .min_voltage = 2800,
-            .max_voltage = 3520,
-            .min_multi = 1.5,
-            .max_multi = 3.5
-        },
-        .bus_flags = MACHINE_PS2_PCI,
-        .flags = MACHINE_IDE_DUAL | MACHINE_APM | MACHINE_ACPI,
-        .ram = {
-            .min = 8192,
-            .max = 262144,
-            .step = 8192
-        },
-        .nvrmask = 255,
-        .kbc_device = NULL,
-        .kbc_p1 = 0xff,
-        .gpio = 0xffffffff,
-        .gpio_acpi = 0xffffffff,
-        .device = NULL,
-        .fdc_device = NULL,
-        .sio_device = NULL,
-        .vid_device = NULL,
-        .snd_device = NULL,
-        .net_device = NULL
-    },
-#endif /* USE_AN430TX */
     /* This has the AMIKey KBC firmware, which is an updated 'F' type. */
     {
         .name = "[i430TX] Intel YM430TX (Yamamoto)",
@@ -13317,9 +13309,13 @@ const machine_t machines[] = {
         .snd_device = NULL,
         .net_device = NULL
     },
-	/* PhoenixBIOS 4.0 Rel 6.0 for 430TX, has onboard Yamaha YMF701 which is not emulated yet. */
-    /* Has a SM(S)C FDC37C935 Super I/O chip with on-chip KBC with Phoenix
-       MultiKey/42 (version 1.38) KBC firmware. */
+    /*
+       PhoenixBIOS 4.0 Rel 6.0 for 430TX, has onboard Yamaha YMF701 which
+       is not emulated yet.
+
+       Has a SM(S)C FDC37C935 Super I/O chip with on-chip KBC with Phoenix
+       MultiKey/42 (version 1.38) KBC firmware.
+     */
     {
         .name = "[i430TX] Micronics Thunderbolt",
         .internal_name = "thunderbolt",
@@ -13341,7 +13337,8 @@ const machine_t machines[] = {
             .max_multi = 3.5
         },
         .bus_flags = MACHINE_PS2_PCI | MACHINE_BUS_USB,
-        .flags = MACHINE_IDE_DUAL | MACHINE_APM | MACHINE_ACPI | MACHINE_GAMEPORT | MACHINE_USB, /* Machine has internal sound: Yamaha YMF701-S */
+        /* Machine has internal sound: Yamaha YMF701-S */
+        .flags = MACHINE_IDE_DUAL | MACHINE_APM | MACHINE_ACPI | MACHINE_GAMEPORT | MACHINE_USB,
         .ram = {
             .min = 8192,
             .max = 262144,
@@ -13400,6 +13397,47 @@ const machine_t machines[] = {
         .snd_device = NULL,
         .net_device = NULL
     },
+    /* This has the Phoenix MultiKey KBC firmware. */
+    {
+        .name = "[i430TX] Packard Bell PB790",
+        .internal_name = "an430tx",
+        .type = MACHINE_TYPE_SOCKET7,
+        .chipset = MACHINE_CHIPSET_INTEL_430TX,
+        .init = machine_at_an430tx_init,
+        .p1_handler = NULL,
+        .gpio_handler = NULL,
+        .available_flag = MACHINE_AVAILABLE,
+        .gpio_acpi_handler = NULL,
+        .cpu = {
+            .package = CPU_PKG_SOCKET5_7,
+            .block = CPU_BLOCK(CPU_K5, CPU_5K86, CPU_K6, CPU_K6_2, CPU_K6_2C, CPU_K6_3, CPU_K6_2P,
+                               CPU_K6_3P, CPU_Cx6x86, CPU_Cx6x86MX, CPU_Cx6x86L),
+            .min_bus = 60000000,
+            .max_bus = 66666667,
+            .min_voltage = 2800,
+            .max_voltage = 3520,
+            .min_multi = 1.5,
+            .max_multi = 3.5
+        },
+        .bus_flags = MACHINE_PS2_PCI,
+        .flags = MACHINE_IDE_DUAL | MACHINE_APM | MACHINE_ACPI,
+        .ram = {
+            .min = 8192,
+            .max = 262144,
+            .step = 8192
+        },
+        .nvrmask = 255,
+        .kbc_device = NULL,
+        .kbc_p1 = 0xff,
+        .gpio = 0xffffffff,
+        .gpio_acpi = 0xffffffff,
+        .device = NULL,
+        .fdc_device = NULL,
+        .sio_device = NULL,
+        .vid_device = NULL,
+        .snd_device = NULL,
+        .net_device = NULL
+    },
     /* The BIOS sends KBC command BB and expects it to output a byte, which is AMI KBC behavior.
        A picture shows a VIA VT82C42N KBC though, so it could be a case of that KBC with AMI firmware. */
     {
@@ -14424,7 +14462,7 @@ const machine_t machines[] = {
         .fdc_device = NULL,
         .sio_device = NULL,
         .vid_device = NULL,
-        .snd_device = &cs4235_device,
+        .snd_device = &cs4235_onboard_device,
         .net_device = NULL
     },
 
@@ -15214,10 +15252,10 @@ const machine_t machines[] = {
        firmwares: AMI '5' MegaKey, Phoenix MultiKey/42 1.37, or Phoenix MultiKey/42i 4.16. */
     {
         .name = "[i440LX] Dell OptiPlex GXa",
-        .internal_name = "optiplex_gxa",
+        .internal_name = "optiplexgxa",
         .type = MACHINE_TYPE_SLOT1,
         .chipset = MACHINE_CHIPSET_INTEL_440LX,
-        .init = machine_at_optiplex_gxa_init,
+        .init = machine_at_optiplexgxa_init,
         .p1_handler = NULL,
         .gpio_handler = NULL,
         .available_flag = MACHINE_AVAILABLE,
diff --git a/src/mem/mem.c b/src/mem/mem.c
index 07d897172..d365ecffb 100644
--- a/src/mem/mem.c
+++ b/src/mem/mem.c
@@ -2994,10 +2994,12 @@ mem_init(void)
 }
 
 static void
-umc_page_recalc(uint32_t c, int set)
+umc_page_recalc(uint32_t c, uint32_t phys, int set)
 {
+    uint32_t target = set ? phys : c;
+
     if (set) {
-        pages[c].mem = &ram[(c & 0xff) << 12];
+        pages[c].mem = &ram[(target & 0xff) << 12];
         pages[c].write_b = mem_write_ramb_page;
         pages[c].write_w = mem_write_ramw_page;
         pages[c].write_l = mem_write_raml_page;
@@ -3010,8 +3012,8 @@ umc_page_recalc(uint32_t c, int set)
 
 #ifdef USE_NEW_DYNAREC
     pages[c].evict_prev             = EVICT_NOT_IN_LIST;
-    pages[c].byte_dirty_mask        = &byte_dirty_mask[(c & 0xff) * 64];
-    pages[c].byte_code_present_mask = &byte_code_present_mask[(c & 0xff) * 64];
+    pages[c].byte_dirty_mask        = &byte_dirty_mask[(target & 0xff) * 64];
+    pages[c].byte_code_present_mask = &byte_code_present_mask[(target & 0xff) * 64];
 #endif
 }
 
@@ -3019,7 +3021,7 @@ void
 umc_smram_recalc(uint32_t start, int set)
 {
     for (uint32_t c = start; c < (start + 0x0020); c++)
-        umc_page_recalc(c, set);
+        umc_page_recalc(c, c - start + 0x000a0000, set);
 }
 
 static void
diff --git a/src/mem/smram.c b/src/mem/smram.c
index afbc5475c..928760f3a 100644
--- a/src/mem/smram.c
+++ b/src/mem/smram.c
@@ -59,9 +59,12 @@ smram_read(uint32_t addr, void *priv)
     const smram_t *dev      = (smram_t *) priv;
     uint32_t       new_addr = addr - dev->host_base + dev->ram_base;
 
+#if (!(defined __amd64__ || defined _M_X64 || defined __aarch64__ || defined _M_ARM64))
     if (new_addr >= (1 << 30))
         return mem_read_ram_2gb(new_addr, priv);
-    else if (!use_separate_smram || (new_addr >= 0xa0000))
+    else
+#endif
+    if (!use_separate_smram || (new_addr >= 0xa0000))
         return mem_read_ram(new_addr, priv);
     else
         return dev->mapping.exec[addr - dev->host_base];
@@ -73,9 +76,12 @@ smram_readw(uint32_t addr, void *priv)
     smram_t *dev      = (smram_t *) priv;
     uint32_t new_addr = addr - dev->host_base + dev->ram_base;
 
+#if (!(defined __amd64__ || defined _M_X64 || defined __aarch64__ || defined _M_ARM64))
     if (new_addr >= (1 << 30))
         return mem_read_ram_2gbw(new_addr, priv);
-    else if (!use_separate_smram || (new_addr >= 0xa0000))
+    else
+#endif
+    if (!use_separate_smram || (new_addr >= 0xa0000))
         return mem_read_ramw(new_addr, priv);
     else
         return *(uint16_t *) &(dev->mapping.exec[addr - dev->host_base]);
@@ -87,9 +93,12 @@ smram_readl(uint32_t addr, void *priv)
     smram_t *dev      = (smram_t *) priv;
     uint32_t new_addr = addr - dev->host_base + dev->ram_base;
 
+#if (!(defined __amd64__ || defined _M_X64 || defined __aarch64__ || defined _M_ARM64))
     if (new_addr >= (1 << 30))
         return mem_read_ram_2gbl(new_addr, priv);
-    else if (!use_separate_smram || (new_addr >= 0xa0000))
+    else
+#endif
+    if (!use_separate_smram || (new_addr >= 0xa0000))
         return mem_read_raml(new_addr, priv);
     else
         return *(uint32_t *) &(dev->mapping.exec[addr - dev->host_base]);
diff --git a/src/pci.c b/src/pci.c
index c3020ca73..94ab9d5f2 100644
--- a/src/pci.c
+++ b/src/pci.c
@@ -855,10 +855,10 @@ pci_register_card(int pci_card)
 
 /* Add an instance of the PCI bridge. */
 void
-pci_add_bridge(uint8_t agp, uint8_t (*read)(int func, int addr, void *priv), void (*write)(int func, int addr, uint8_t val, void *priv), void *priv, uint8_t *slot)
+pci_add_bridge(uint8_t add_type, uint8_t (*read)(int func, int addr, void *priv), void (*write)(int func, int addr, uint8_t val, void *priv), void *priv, uint8_t *slot)
 {
     pci_card_t *card;
-    uint8_t bridge_slot = agp ? pci_find_slot(PCI_ADD_AGPBRIDGE, 0xff) : last_normal_pci_card_id;
+    uint8_t bridge_slot = (add_type == PCI_ADD_NORMAL) ? last_normal_pci_card_id : pci_find_slot(add_type, 0xff);
 
     if (bridge_slot != PCI_CARD_INVALID) {
         card = &pci_cards[bridge_slot];
diff --git a/src/qt/qt_harddiskdialog.cpp b/src/qt/qt_harddiskdialog.cpp
index 9e5563536..ae1c60971 100644
--- a/src/qt/qt_harddiskdialog.cpp
+++ b/src/qt/qt_harddiskdialog.cpp
@@ -199,7 +199,7 @@ HarddiskDialog::on_comboBoxFormat_currentIndexChanged(int index)
  * than a tenth of a percent change in size.
  */
 static void
-adjust_86box_geometry_for_vhd(MVHDGeom *_86box_geometry, MVHDGeom *vhd_geometry)
+adjust_86box_geometry_for_vhd(_86BoxGeom *_86box_geometry, MVHDGeom *vhd_geometry)
 {
     if (_86box_geometry->cyl <= 65535) {
         vhd_geometry->cyl   = _86box_geometry->cyl;
@@ -226,10 +226,10 @@ adjust_86box_geometry_for_vhd(MVHDGeom *_86box_geometry, MVHDGeom *vhd_geometry)
 }
 
 static HarddiskDialog *callbackPtr = nullptr;
-static MVHDGeom
-create_drive_vhd_fixed(const QString &fileName, HarddiskDialog *p, uint16_t cyl, uint8_t heads, uint8_t spt)
+static _86BoxGeom
+create_drive_vhd_fixed(const QString &fileName, HarddiskDialog *p, uint32_t cyl, uint32_t heads, uint32_t spt)
 {
-    MVHDGeom _86box_geometry = {
+    _86BoxGeom _86box_geometry = {
         .cyl   = cyl,
         .heads = heads,
         .spt   = spt
@@ -256,10 +256,10 @@ create_drive_vhd_fixed(const QString &fileName, HarddiskDialog *p, uint16_t cyl,
     return _86box_geometry;
 }
 
-static MVHDGeom
-create_drive_vhd_dynamic(const QString &fileName, uint16_t cyl, uint8_t heads, uint8_t spt, int blocksize)
+static _86BoxGeom
+create_drive_vhd_dynamic(const QString &fileName, uint32_t cyl, uint32_t heads, uint32_t spt, int blocksize)
 {
-    MVHDGeom _86box_geometry = {
+    _86BoxGeom _86box_geometry = {
         .cyl   = cyl,
         .heads = heads,
         .spt   = spt
@@ -287,7 +287,7 @@ create_drive_vhd_dynamic(const QString &fileName, uint16_t cyl, uint8_t heads, u
     return _86box_geometry;
 }
 
-static MVHDGeom
+static _86BoxGeom
 create_drive_vhd_diff(const QString &fileName, const QString &parentFileName, int blocksize)
 {
     int                 vhd_error           = 0;
@@ -299,25 +299,31 @@ create_drive_vhd_diff(const QString &fileName, const QString &parentFileName, in
     options.parent_path           = parentFilenameBytes.data();
     options.type                  = MVHD_TYPE_DIFF;
 
-    MVHDMeta *vhd = mvhd_create_ex(options, &vhd_error);
-    MVHDGeom  vhd_geometry;
+    MVHDMeta  *vhd = mvhd_create_ex(options, &vhd_error);
+    MVHDGeom   vhd_geometry;
+    _86BoxGeom _86box_geometry;
     if (vhd == NULL) {
-        vhd_geometry.cyl   = 0;
-        vhd_geometry.heads = 0;
-        vhd_geometry.spt   = 0;
+        _86box_geometry.cyl   = 0;
+        _86box_geometry.heads = 0;
+        _86box_geometry.spt   = 0;
     } else {
         vhd_geometry = mvhd_get_geometry(vhd);
 
         if (vhd_geometry.spt > 63) {
-            vhd_geometry.cyl   = mvhd_calc_size_sectors(&vhd_geometry) / (16 * 63);
-            vhd_geometry.heads = 16;
-            vhd_geometry.spt   = 63;
+            _86box_geometry.cyl   = mvhd_calc_size_sectors(&vhd_geometry) / (16 * 63);
+            _86box_geometry.heads = 16;
+            _86box_geometry.spt   = 63;
+        } else {
+            _86box_geometry.cyl   = vhd_geometry.cyl;
+            _86box_geometry.heads = vhd_geometry.heads;
+            _86box_geometry.spt   = vhd_geometry.spt;
         }
 
+
         mvhd_close(vhd);
     }
 
-    return vhd_geometry;
+    return _86box_geometry;
 }
 
 void
@@ -409,7 +415,7 @@ HarddiskDialog::onCreateNewFile()
     } else if (img_format >= IMG_FMT_VHD_FIXED) { /* VHD file */
         file.close();
 
-        MVHDGeom _86box_geometry {};
+        _86BoxGeom _86box_geometry {};
         int      block_size = ui->comboBoxBlockSize->currentIndex() == 0 ? MVHD_BLOCK_LARGE : MVHD_BLOCK_SMALL;
         switch (img_format) {
             case IMG_FMT_VHD_FIXED:
@@ -493,10 +499,14 @@ HarddiskDialog::onCreateNewFile()
 }
 
 static void
-adjust_vhd_geometry_for_86box(MVHDGeom *vhd_geometry)
+adjust_vhd_geometry_for_86box(MVHDGeom *vhd_geometry, _86BoxGeom *_86box_geometry)
 {
-    if (vhd_geometry->spt <= 63)
+    if (vhd_geometry->spt <= 63) {
+        _86box_geometry->cyl   = vhd_geometry->cyl;
+        _86box_geometry->heads = vhd_geometry->heads;
+        _86box_geometry->spt   = vhd_geometry->spt;
         return;
+    }
 
     int desired_sectors = vhd_geometry->cyl * vhd_geometry->heads * vhd_geometry->spt;
     if (desired_sectors > 267321600)
@@ -506,9 +516,9 @@ adjust_vhd_geometry_for_86box(MVHDGeom *vhd_geometry)
     if (remainder > 0)
         desired_sectors -= remainder;
 
-    vhd_geometry->cyl   = desired_sectors / (16 * 63);
-    vhd_geometry->heads = 16;
-    vhd_geometry->spt   = 63;
+    _86box_geometry->cyl   = desired_sectors / (16 * 63);
+    _86box_geometry->heads = 16;
+    _86box_geometry->spt   = 63;
 }
 
 void
@@ -602,11 +612,12 @@ HarddiskDialog::onExistingFileSelected(const QString &fileName, bool precheck)
             }
         }
 
-        MVHDGeom vhd_geom = mvhd_get_geometry(vhd);
-        adjust_vhd_geometry_for_86box(&vhd_geom);
-        cylinders = vhd_geom.cyl;
-        heads     = vhd_geom.heads;
-        sectors   = vhd_geom.spt;
+        MVHDGeom   vhd_geom = mvhd_get_geometry(vhd);
+        _86BoxGeom _86box_geom;
+        adjust_vhd_geometry_for_86box(&vhd_geom, &_86box_geom);
+        cylinders = _86box_geom.cyl;
+        heads     = _86box_geom.heads;
+        sectors   = _86box_geom.spt;
         size      = static_cast<uint64_t>(cylinders * heads * sectors * 512);
         mvhd_close(vhd);
     } else {
diff --git a/src/qt/qt_harddiskdialog.hpp b/src/qt/qt_harddiskdialog.hpp
index 9de61c51b..62ec6e963 100644
--- a/src/qt/qt_harddiskdialog.hpp
+++ b/src/qt/qt_harddiskdialog.hpp
@@ -64,4 +64,10 @@ private:
     void recalcSelection();
 };
 
+typedef struct _86BoxGeom {
+    uint32_t cyl;
+    uint32_t heads;
+    uint32_t spt;
+} _86BoxGeom;
+
 #endif // QT_HARDDISKDIALOG_HPP
diff --git a/src/sio/sio_detect.c b/src/sio/sio_detect.c
index ffa0ec9d0..d36522fe0 100644
--- a/src/sio/sio_detect.c
+++ b/src/sio/sio_detect.c
@@ -47,11 +47,12 @@ sio_detect_write(uint16_t port, uint8_t val, void *priv)
 static uint8_t
 sio_detect_read(uint16_t port, void *priv)
 {
-    const sio_detect_t *dev = (sio_detect_t *) priv;
+    /*const sio_detect_t *dev = (sio_detect_t *) priv*/;
+    uint8_t             ret = 0xff /*dev->regs[port & 1]*/;
 
-    pclog("sio_detect_read : port=%04x = %02X\n", port, dev->regs[port & 1]);
+    pclog("sio_detect_read : port=%04x = %02X\n", port, ret);
 
-    return 0xff /*dev->regs[port & 1]*/;
+    return ret;
 }
 
 static void
diff --git a/src/sound/CMakeLists.txt b/src/sound/CMakeLists.txt
index 0a04b0ff1..66a0ee4e3 100644
--- a/src/sound/CMakeLists.txt
+++ b/src/sound/CMakeLists.txt
@@ -41,6 +41,7 @@ add_library(snd OBJECT
     snd_sb.c
     snd_sb_dsp.c
     snd_emu8k.c
+    snd_mmb.c
     snd_mpu401.c
     snd_pas16.c
     snd_sn76489.c
@@ -48,8 +49,6 @@ add_library(snd OBJECT
     snd_wss.c
     snd_ym7128.c
     snd_optimc.c
-    esfmu/esfm.c
-    esfmu/esfm_registers.c
     snd_opl_esfm.c
 )
 
@@ -177,20 +176,22 @@ if(MUNT)
     endif()
 endif()
 
+add_subdirectory(ayumi)
+target_link_libraries(86Box ayumi)
+
+add_subdirectory(esfmu)
+target_link_libraries(86Box esfmu)
+
 add_subdirectory(ymfm)
 target_link_libraries(86Box ymfm)
 
-if(GUSMAX)
-    target_compile_definitions(snd PRIVATE USE_GUSMAX)
-endif()
-
 if(OPL4ML)
     target_compile_definitions(snd PRIVATE USE_OPL4ML)
     target_sources(snd PRIVATE midi_opl4.c midi_opl4_yrw801.c)
 endif()
  
-find_package(PkgConfig )
-pkg_check_modules(SERIALPORT  libserialport)
+find_package(PkgConfig)
+pkg_check_modules(SERIALPORT libserialport)
 
 if(SERIALPORT_FOUND OR DEFINED LIBSERIALPORT_ROOT)
     add_compile_definitions(USE_LIBSERIALPORT=1)
diff --git a/src/sound/ayumi/CMakeLists.txt b/src/sound/ayumi/CMakeLists.txt
new file mode 100644
index 000000000..f3e4b18c7
--- /dev/null
+++ b/src/sound/ayumi/CMakeLists.txt
@@ -0,0 +1,14 @@
+#
+# 86Box    A hypervisor and IBM PC system emulator that specializes in
+#          running old operating systems and software designed for IBM
+#          PC systems and compatibles from 1981 through fairly recent
+#          system designs based on the PCI bus.
+#
+#          This file is part of the 86Box distribution.
+#
+#          CMake build script.
+#
+
+add_library(ayumi STATIC
+    ayumi.c
+)
diff --git a/src/sound/ayumi/LICENSE b/src/sound/ayumi/LICENSE
new file mode 100644
index 000000000..25371edc6
--- /dev/null
+++ b/src/sound/ayumi/LICENSE
@@ -0,0 +1,21 @@
+The MIT License
+
+Copyright (c) Peter Sovietov, http://sovietov.com
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in
+all copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+THE SOFTWARE.
\ No newline at end of file
diff --git a/src/sound/ayumi/ayumi.c b/src/sound/ayumi/ayumi.c
new file mode 100644
index 000000000..861b0fd45
--- /dev/null
+++ b/src/sound/ayumi/ayumi.c
@@ -0,0 +1,338 @@
+/* Author: Peter Sovietov */
+
+#include <string.h>
+#include <math.h>
+#include "ayumi.h"
+
+static const double AY_dac_table[] = {
+  0.0, 0.0,
+  0.00999465934234, 0.00999465934234,
+  0.0144502937362, 0.0144502937362,
+  0.0210574502174, 0.0210574502174,
+  0.0307011520562, 0.0307011520562,
+  0.0455481803616, 0.0455481803616,
+  0.0644998855573, 0.0644998855573,
+  0.107362478065, 0.107362478065,
+  0.126588845655, 0.126588845655,
+  0.20498970016, 0.20498970016,
+  0.292210269322, 0.292210269322,
+  0.372838941024, 0.372838941024,
+  0.492530708782, 0.492530708782,
+  0.635324635691, 0.635324635691,
+  0.805584802014, 0.805584802014,
+  1.0, 1.0
+};
+
+static const double YM_dac_table[] = {
+  0.0, 0.0,
+  0.00465400167849, 0.00772106507973,
+  0.0109559777218, 0.0139620050355,
+  0.0169985503929, 0.0200198367285,
+  0.024368657969, 0.029694056611,
+  0.0350652323186, 0.0403906309606,
+  0.0485389486534, 0.0583352407111,
+  0.0680552376593, 0.0777752346075,
+  0.0925154497597, 0.111085679408,
+  0.129747463188, 0.148485542077,
+  0.17666895552, 0.211551079576,
+  0.246387426566, 0.281101701381,
+  0.333730067903, 0.400427252613,
+  0.467383840696, 0.53443198291,
+  0.635172045472, 0.75800717174,
+  0.879926756695, 1.0
+};
+
+static void reset_segment(struct ayumi* ay);
+
+static int update_tone(struct ayumi* ay, int index) {
+  struct tone_channel* ch = &ay->channels[index];
+  ch->tone_counter += 1;
+  if (ch->tone_counter >= ch->tone_period) {
+    ch->tone_counter = 0;
+    ch->tone ^= 1;
+  }
+  return ch->tone;
+}
+
+static int update_noise(struct ayumi* ay) {
+  int bit0x3;
+  ay->noise_counter += 1;
+  if (ay->noise_counter >= (ay->noise_period << 1)) {
+    ay->noise_counter = 0;
+    bit0x3 = ((ay->noise ^ (ay->noise >> 3)) & 1);
+    ay->noise = (ay->noise >> 1) | (bit0x3 << 16);
+  }
+  return ay->noise & 1;
+}
+
+static void slide_up(struct ayumi* ay) {
+  ay->envelope += 1;
+  if (ay->envelope > 31) {
+    ay->envelope_segment ^= 1;
+    reset_segment(ay);
+  }
+}
+
+static void slide_down(struct ayumi* ay) {
+  ay->envelope -= 1;
+  if (ay->envelope < 0) {
+    ay->envelope_segment ^= 1;
+    reset_segment(ay);
+  }
+}
+
+static void hold_top(struct ayumi* ay) {
+  (void) ay;
+}
+
+static void hold_bottom(struct ayumi* ay) {
+  (void) ay;
+}
+
+static void (* const Envelopes[][2])(struct ayumi*) = {
+  {slide_down, hold_bottom},
+  {slide_down, hold_bottom},
+  {slide_down, hold_bottom},
+  {slide_down, hold_bottom},
+  {slide_up, hold_bottom},
+  {slide_up, hold_bottom},
+  {slide_up, hold_bottom},
+  {slide_up, hold_bottom},
+  {slide_down, slide_down},
+  {slide_down, hold_bottom},
+  {slide_down, slide_up},
+  {slide_down, hold_top},
+  {slide_up, slide_up},
+  {slide_up, hold_top},
+  {slide_up, slide_down},
+  {slide_up, hold_bottom}
+};
+
+static void reset_segment(struct ayumi* ay) {
+  if (Envelopes[ay->envelope_shape][ay->envelope_segment] == slide_down
+    || Envelopes[ay->envelope_shape][ay->envelope_segment] == hold_top) {
+    ay->envelope = 31;
+    return;
+  }
+  ay->envelope = 0;
+}
+
+int update_envelope(struct ayumi* ay) {
+  ay->envelope_counter += 1;
+  if (ay->envelope_counter >= ay->envelope_period) {
+    ay->envelope_counter = 0;
+    Envelopes[ay->envelope_shape][ay->envelope_segment](ay);
+  }
+  return ay->envelope;
+}
+
+static void update_mixer(struct ayumi* ay) {
+  int i;
+  int out;
+  int noise = update_noise(ay);
+  int envelope = update_envelope(ay);
+  ay->left = 0;
+  ay->right = 0;
+  for (i = 0; i < TONE_CHANNELS; i += 1) {
+    out = (update_tone(ay, i) | ay->channels[i].t_off) & (noise | ay->channels[i].n_off);
+    out *= ay->channels[i].e_on ? envelope : ay->channels[i].volume * 2 + 1;
+    ay->left += ay->dac_table[out] * ay->channels[i].pan_left;
+    ay->right += ay->dac_table[out] * ay->channels[i].pan_right;
+  }
+}
+
+int ayumi_configure(struct ayumi* ay, int is_ym, double clock_rate, int sr) {
+  int i;
+  memset(ay, 0, sizeof(struct ayumi));
+  ay->step = clock_rate / (sr * 8 * DECIMATE_FACTOR);
+  ay->dac_table = is_ym ? YM_dac_table : AY_dac_table;
+  ay->noise = 1;
+  ayumi_set_envelope(ay, 1);
+  for (i = 0; i < TONE_CHANNELS; i += 1) {
+    ayumi_set_tone(ay, i, 1);
+  }
+  return ay->step < 1;
+}
+
+void ayumi_set_pan(struct ayumi* ay, int index, double pan, int is_eqp) {
+  if (is_eqp) {
+    ay->channels[index].pan_left = sqrt(1 - pan);
+    ay->channels[index].pan_right = sqrt(pan);
+  } else {
+    ay->channels[index].pan_left = 1 - pan;
+    ay->channels[index].pan_right = pan;
+  }
+}
+
+void ayumi_set_tone(struct ayumi* ay, int index, int period) {
+  period &= 0xfff;
+  ay->channels[index].tone_period = (period == 0) | period;
+}
+
+void ayumi_set_noise(struct ayumi* ay, int period) {
+  period &= 0x1f;
+  ay->noise_period = (period == 0) | period;
+}
+
+void ayumi_set_mixer(struct ayumi* ay, int index, int t_off, int n_off, int e_on) {
+  ay->channels[index].t_off = t_off & 1;
+  ay->channels[index].n_off = n_off & 1;
+  ay->channels[index].e_on = e_on;
+}
+
+void ayumi_set_volume(struct ayumi* ay, int index, int volume) {
+  ay->channels[index].volume = volume & 0xf;
+}
+
+void ayumi_set_envelope(struct ayumi* ay, int period) {
+  period &= 0xffff;
+  ay->envelope_period = (period == 0) | period;
+}
+
+void ayumi_set_envelope_shape(struct ayumi* ay, int shape) {
+  ay->envelope_shape = shape & 0xf;
+  ay->envelope_counter = 0;
+  ay->envelope_segment = 0;
+  reset_segment(ay);
+}
+
+static double decimate(double* x) {
+  double y = -0.0000046183113992051936 * (x[1] + x[191]) +
+    -0.00001117761640887225 * (x[2] + x[190]) +
+    -0.000018610264502005432 * (x[3] + x[189]) +
+    -0.000025134586135631012 * (x[4] + x[188]) +
+    -0.000028494281690666197 * (x[5] + x[187]) +
+    -0.000026396828793275159 * (x[6] + x[186]) +
+    -0.000017094212558802156 * (x[7] + x[185]) +
+    0.000023798193576966866 * (x[9] + x[183]) +
+    0.000051281160242202183 * (x[10] + x[182]) +
+    0.00007762197826243427 * (x[11] + x[181]) +
+    0.000096759426664120416 * (x[12] + x[180]) +
+    0.00010240229300393402 * (x[13] + x[179]) +
+    0.000089344614218077106 * (x[14] + x[178]) +
+    0.000054875700118949183 * (x[15] + x[177]) +
+    -0.000069839082210680165 * (x[17] + x[175]) +
+    -0.0001447966132360757 * (x[18] + x[174]) +
+    -0.00021158452917708308 * (x[19] + x[173]) +
+    -0.00025535069106550544 * (x[20] + x[172]) +
+    -0.00026228714374322104 * (x[21] + x[171]) +
+    -0.00022258805927027799 * (x[22] + x[170]) +
+    -0.00013323230495695704 * (x[23] + x[169]) +
+    0.00016182578767055206 * (x[25] + x[167]) +
+    0.00032846175385096581 * (x[26] + x[166]) +
+    0.00047045611576184863 * (x[27] + x[165]) +
+    0.00055713851457530944 * (x[28] + x[164]) +
+    0.00056212565121518726 * (x[29] + x[163]) +
+    0.00046901918553962478 * (x[30] + x[162]) +
+    0.00027624866838952986 * (x[31] + x[161]) +
+    -0.00032564179486838622 * (x[33] + x[159]) +
+    -0.00065182310286710388 * (x[34] + x[158]) +
+    -0.00092127787309319298 * (x[35] + x[157]) +
+    -0.0010772534348943575 * (x[36] + x[156]) +
+    -0.0010737727700273478 * (x[37] + x[155]) +
+    -0.00088556645390392634 * (x[38] + x[154]) +
+    -0.00051581896090765534 * (x[39] + x[153]) +
+    0.00059548767193795277 * (x[41] + x[151]) +
+    0.0011803558710661009 * (x[42] + x[150]) +
+    0.0016527320270369871 * (x[43] + x[149]) +
+    0.0019152679330965555 * (x[44] + x[148]) +
+    0.0018927324805381538 * (x[45] + x[147]) +
+    0.0015481870327877937 * (x[46] + x[146]) +
+    0.00089470695834941306 * (x[47] + x[145]) +
+    -0.0010178225878206125 * (x[49] + x[143]) +
+    -0.0020037400552054292 * (x[50] + x[142]) +
+    -0.0027874356824117317 * (x[51] + x[141]) +
+    -0.003210329988021943 * (x[52] + x[140]) +
+    -0.0031540624117984395 * (x[53] + x[139]) +
+    -0.0025657163651900345 * (x[54] + x[138]) +
+    -0.0014750752642111449 * (x[55] + x[137]) +
+    0.0016624165446378462 * (x[57] + x[135]) +
+    0.0032591192839069179 * (x[58] + x[134]) +
+    0.0045165685815867747 * (x[59] + x[133]) +
+    0.0051838984346123896 * (x[60] + x[132]) +
+    0.0050774264697459933 * (x[61] + x[131]) +
+    0.0041192521414141585 * (x[62] + x[130]) +
+    0.0023628575417966491 * (x[63] + x[129]) +
+    -0.0026543507866759182 * (x[65] + x[127]) +
+    -0.0051990251084333425 * (x[66] + x[126]) +
+    -0.0072020238234656924 * (x[67] + x[125]) +
+    -0.0082672928192007358 * (x[68] + x[124]) +
+    -0.0081033739572956287 * (x[69] + x[123]) +
+    -0.006583111539570221 * (x[70] + x[122]) +
+    -0.0037839040415292386 * (x[71] + x[121]) +
+    0.0042781252851152507 * (x[73] + x[119]) +
+    0.0084176358598320178 * (x[74] + x[118]) +
+    0.01172566057463055 * (x[75] + x[117]) +
+    0.013550476647788672 * (x[76] + x[116]) +
+    0.013388189369997496 * (x[77] + x[115]) +
+    0.010979501242341259 * (x[78] + x[114]) +
+    0.006381274941685413 * (x[79] + x[113]) +
+    -0.007421229604153888 * (x[81] + x[111]) +
+    -0.01486456304340213 * (x[82] + x[110]) +
+    -0.021143584622178104 * (x[83] + x[109]) +
+    -0.02504275058758609 * (x[84] + x[108]) +
+    -0.025473530942547201 * (x[85] + x[107]) +
+    -0.021627310017882196 * (x[86] + x[106]) +
+    -0.013104323383225543 * (x[87] + x[105]) +
+    0.017065133989980476 * (x[89] + x[103]) +
+    0.036978919264451952 * (x[90] + x[102]) +
+    0.05823318062093958 * (x[91] + x[101]) +
+    0.079072012081405949 * (x[92] + x[100]) +
+    0.097675998716952317 * (x[93] + x[99]) +
+    0.11236045936950932 * (x[94] + x[98]) +
+    0.12176343577287731 * (x[95] + x[97]) +
+    0.125 * x[96];
+  memcpy(&x[FIR_SIZE - DECIMATE_FACTOR], x, DECIMATE_FACTOR * sizeof(double));
+  return y;
+}
+
+void ayumi_process(struct ayumi* ay) {
+  int i;
+  double y1;
+  double* c_left = ay->interpolator_left.c;
+  double* y_left = ay->interpolator_left.y;
+  double* c_right = ay->interpolator_right.c;
+  double* y_right = ay->interpolator_right.y;
+  double* fir_left = &ay->fir_left[FIR_SIZE - ay->fir_index * DECIMATE_FACTOR];
+  double* fir_right = &ay->fir_right[FIR_SIZE - ay->fir_index * DECIMATE_FACTOR];
+  ay->fir_index = (ay->fir_index + 1) % (FIR_SIZE / DECIMATE_FACTOR - 1);
+  for (i = DECIMATE_FACTOR - 1; i >= 0; i -= 1) {
+    ay->x += ay->step;
+    if (ay->x >= 1) {
+      ay->x -= 1;
+      y_left[0] = y_left[1];
+      y_left[1] = y_left[2];
+      y_left[2] = y_left[3];
+      y_right[0] = y_right[1];
+      y_right[1] = y_right[2];
+      y_right[2] = y_right[3];
+      update_mixer(ay);
+      y_left[3] = ay->left;
+      y_right[3] = ay->right;
+      y1 = y_left[2] - y_left[0];
+      c_left[0] = 0.5 * y_left[1] + 0.25 * (y_left[0] + y_left[2]);
+      c_left[1] = 0.5 * y1;
+      c_left[2] = 0.25 * (y_left[3] - y_left[1] - y1);
+      y1 = y_right[2] - y_right[0];
+      c_right[0] = 0.5 * y_right[1] + 0.25 * (y_right[0] + y_right[2]);
+      c_right[1] = 0.5 * y1;
+      c_right[2] = 0.25 * (y_right[3] - y_right[1] - y1);
+    }
+    fir_left[i] = (c_left[2] * ay->x + c_left[1]) * ay->x + c_left[0];
+    fir_right[i] = (c_right[2] * ay->x + c_right[1]) * ay->x + c_right[0];
+  }
+  ay->left = decimate(fir_left);
+  ay->right = decimate(fir_right);
+}
+
+static double dc_filter(struct dc_filter* dc, int index, double x) {
+  dc->sum += -dc->delay[index] + x;
+  dc->delay[index] = x; 
+  return x - dc->sum / DC_FILTER_SIZE;
+}
+
+void ayumi_remove_dc(struct ayumi* ay) {
+  ay->left = dc_filter(&ay->dc_left, ay->dc_index, ay->left);
+  ay->right = dc_filter(&ay->dc_right, ay->dc_index, ay->right);
+  ay->dc_index = (ay->dc_index + 1) & (DC_FILTER_SIZE - 1);
+}
diff --git a/src/sound/ayumi/ayumi.h b/src/sound/ayumi/ayumi.h
new file mode 100644
index 000000000..f15939514
--- /dev/null
+++ b/src/sound/ayumi/ayumi.h
@@ -0,0 +1,71 @@
+/* Author: Peter Sovietov */
+
+#ifndef AYUMI_H
+#define AYUMI_H
+
+enum {
+  TONE_CHANNELS = 3,
+  DECIMATE_FACTOR = 8,
+  FIR_SIZE = 192,
+  DC_FILTER_SIZE = 1024
+};
+
+struct tone_channel {
+  int tone_period;
+  int tone_counter;
+  int tone;
+  int t_off;
+  int n_off;
+  int e_on;
+  int volume;
+  double pan_left;
+  double pan_right;
+};
+
+struct interpolator {
+  double c[4];
+  double y[4];
+};
+
+struct dc_filter {
+  double sum;
+  double delay[DC_FILTER_SIZE];
+};
+
+struct ayumi {
+  struct tone_channel channels[TONE_CHANNELS];
+  int noise_period;
+  int noise_counter;
+  int noise;
+  int envelope_counter;
+  int envelope_period;
+  int envelope_shape;
+  int envelope_segment;
+  int envelope;
+  const double* dac_table;
+  double step;
+  double x;
+  struct interpolator interpolator_left;
+  struct interpolator interpolator_right;
+  double fir_left[FIR_SIZE * 2];
+  double fir_right[FIR_SIZE * 2];
+  int fir_index;
+  struct dc_filter dc_left;
+  struct dc_filter dc_right;
+  int dc_index;
+  double left;
+  double right;
+};
+
+int ayumi_configure(struct ayumi* ay, int is_ym, double clock_rate, int sr);
+void ayumi_set_pan(struct ayumi* ay, int index, double pan, int is_eqp);
+void ayumi_set_tone(struct ayumi* ay, int index, int period);
+void ayumi_set_noise(struct ayumi* ay, int period);
+void ayumi_set_mixer(struct ayumi* ay, int index, int t_off, int n_off, int e_on);
+void ayumi_set_volume(struct ayumi* ay, int index, int volume);
+void ayumi_set_envelope(struct ayumi* ay, int period);
+void ayumi_set_envelope_shape(struct ayumi* ay, int shape);
+void ayumi_process(struct ayumi* ay);
+void ayumi_remove_dc(struct ayumi* ay);
+
+#endif
diff --git a/src/sound/esfmu/CMakeLists.txt b/src/sound/esfmu/CMakeLists.txt
new file mode 100644
index 000000000..2505038f1
--- /dev/null
+++ b/src/sound/esfmu/CMakeLists.txt
@@ -0,0 +1,15 @@
+#
+# 86Box    A hypervisor and IBM PC system emulator that specializes in
+#          running old operating systems and software designed for IBM
+#          PC systems and compatibles from 1981 through fairly recent
+#          system designs based on the PCI bus.
+#
+#          This file is part of the 86Box distribution.
+#
+#          CMake build script.
+#
+
+add_library(esfmu STATIC
+    esfm.c
+    esfm_registers.c
+)
diff --git a/src/sound/snd_cs423x.c b/src/sound/snd_cs423x.c
index 17ea48dd3..74382a53b 100644
--- a/src/sound/snd_cs423x.c
+++ b/src/sound/snd_cs423x.c
@@ -650,15 +650,7 @@ cs423x_pnp_enable(cs423x_t *dev, uint8_t update_rom, uint8_t update_hwconfig)
             isapnp_update_card_rom(dev->pnp_card, &dev->ram_data[dev->pnp_offset], dev->pnp_size);
 
         /* Disable PnP key if the PKD bit is set, or if it was disabled by command 0x55. */
-        /* But wait! The TriGem Delhi-III BIOS sends command 0x55, and its behavior doesn't
-           line up with real hardware (still listed in the POST summary and seen by software).
-           Disable the PnP key disabling mechanism until someone figures something out. */
-#if 0
         isapnp_enable_card(dev->pnp_card, ((dev->ram_data[0x4002] & 0x20) || !dev->pnp_enable) ? ISAPNP_CARD_NO_KEY : ISAPNP_CARD_ENABLE);
-#else
-        if ((dev->ram_data[0x4002] & 0x20) || !dev->pnp_enable)
-            pclog("CS423x: Attempted to disable PnP key\n");
-#endif
     }
 
     /* Update some register bits based on the config data in RAM if requested. */
diff --git a/src/sound/snd_gus.c b/src/sound/snd_gus.c
index 1885581a5..fff679e81 100644
--- a/src/sound/snd_gus.c
+++ b/src/sound/snd_gus.c
@@ -17,9 +17,7 @@
 #include <86box/sound.h>
 #include "cpu.h"
 #include <86box/timer.h>
-#ifdef USE_GUSMAX
-#    include <86box/snd_ad1848.h>
-#endif /*USE_GUSMAX */
+#include <86box/snd_ad1848.h>
 #include <86box/plat_fallthrough.h>
 #include <86box/plat_unused.h>
 
@@ -145,11 +143,9 @@ typedef struct gus_t {
 
     uint8_t usrr;
 
-#ifdef USE_GUSMAX
     uint8_t max_ctrl;
 
     ad1848_t ad1848;
-#endif /*USE_GUSMAX */
 } gus_t;
 
 static int gus_gf1_irqs[8]  = { -1, 2, 5, 3, 7, 11, 12, 15 };
@@ -257,9 +253,7 @@ writegus(uint16_t addr, uint8_t val, void *priv)
     int      d;
     int      old;
     uint16_t port;
-#ifdef USE_GUSMAX
     uint16_t csioport;
-#endif /*USE_GUSMAX */
 
     if ((addr == 0x388) || (addr == 0x389))
         port = addr;
@@ -607,10 +601,9 @@ writegus(uint16_t addr, uint8_t val, void *priv)
                                 gus->irq_midi = gus->irq;
                         } else
                             gus->irq_midi = gus_midi_irqs[(val >> 3) & 7];
-#ifdef USE_GUSMAX
+
                         if (gus->type == GUS_MAX)
                             ad1848_setirq(&gus->ad1848, gus->irq);
-#endif /*USE_GUSMAX */
 
                         gus->sb_nmi = val & 0x80;
                     } else {
@@ -623,10 +616,9 @@ writegus(uint16_t addr, uint8_t val, void *priv)
                                 gus->dma2 = gus->dma;
                         } else
                             gus->dma2 = gus_dmas[(val >> 3) & 7];
-#ifdef USE_GUSMAX
+
                         if (gus->type == GUS_MAX)
                             ad1848_setdma(&gus->ad1848, gus->dma2);
-#endif /*USE_GUSMAX */
                     }
                     break;
                 case 1:
@@ -684,7 +676,6 @@ writegus(uint16_t addr, uint8_t val, void *priv)
             break;
         case 0x306:
         case 0x706:
-#ifdef USE_GUSMAX
             if (gus->type == GUS_MAX) {
                 if (gus->dma >= 4)
                     val |= 0x10;
@@ -704,7 +695,6 @@ writegus(uint16_t addr, uint8_t val, void *priv)
                     }
                 }
             }
-#endif /*USE_GUSMAX */
             break;
 
         default:
@@ -756,11 +746,9 @@ readgus(uint16_t addr, void *priv)
             return val;
 
         case 0x20F:
-#ifdef USE_GUSMAX
             if (gus->type == GUS_MAX)
                 val = 0x02;
             else
-#endif /*USE_GUSMAX */
                 val = 0x00;
             break;
 
@@ -879,11 +867,9 @@ readgus(uint16_t addr, void *priv)
             break;
         case 0x306:
         case 0x706:
-#ifdef USE_GUSMAX
             if (gus->type == GUS_MAX)
                 val = 0x0a; /* GUS MAX */
             else
-#endif /*USE_GUSMAX */
                 val = 0xff; /*Pre 3.7 - no mixer*/
             break;
 
@@ -1183,24 +1169,20 @@ gus_get_buffer(int32_t *buffer, int len, void *priv)
 {
     gus_t *gus = (gus_t *) priv;
 
-#ifdef USE_GUSMAX
     if ((gus->type == GUS_MAX) && (gus->max_ctrl))
         ad1848_update(&gus->ad1848);
-#endif /*USE_GUSMAX */
+
     gus_update(gus);
 
     for (int c = 0; c < len * 2; c++) {
-#ifdef USE_GUSMAX
         if ((gus->type == GUS_MAX) && (gus->max_ctrl))
             buffer[c] += (int32_t) (gus->ad1848.buffer[c] / 2);
-#endif /*USE_GUSMAX */
         buffer[c] += (int32_t) gus->buffer[c & 1][c >> 1];
     }
 
-#ifdef USE_GUSMAX
     if ((gus->type == GUS_MAX) && (gus->max_ctrl))
         gus->ad1848.pos = 0;
-#endif /*USE_GUSMAX */
+
     gus->pos = 0;
 }
 
@@ -1333,9 +1315,7 @@ gus_reset(void *priv)
 
     gus->usrr = 0;
 
-#ifdef USE_GUSMAX
     gus->max_ctrl = 0;
-#endif /*USE_GUSMAX */
 
     gus->irq_state = 0;
     gus->midi_irq_state = 0;
@@ -1373,7 +1353,7 @@ gus_init(UNUSED(const device_t *info))
 
     gus->uart_out = 1;
 
-    gus->type = device_get_config_int("type");
+    gus->type = info->local;
 
     gus->base = device_get_config_hex16("base");
 
@@ -1382,7 +1362,6 @@ gus_init(UNUSED(const device_t *info))
     io_sethandler(0x0506 + gus->base, 0x0001, readgus, NULL, NULL, writegus, NULL, NULL, gus);
     io_sethandler(0x0388, 0x0002, readgus, NULL, NULL, writegus, NULL, NULL, gus);
 
-#ifdef USE_GUSMAX
     if (gus->type == GUS_MAX) {
         ad1848_init(&gus->ad1848, AD1848_TYPE_CS4231);
         ad1848_setirq(&gus->ad1848, 5);
@@ -1390,7 +1369,6 @@ gus_init(UNUSED(const device_t *info))
         io_sethandler(0x10C + gus->base, 4,
                       ad1848_read, NULL, NULL, ad1848_write, NULL, NULL, &gus->ad1848);
     }
-#endif /*USE_GUSMAX */
 
     timer_add(&gus->samp_timer, gus_poll_wave, gus, 1);
     timer_add(&gus->timer_1, gus_poll_timer_1, gus, 1);
@@ -1423,31 +1401,12 @@ gus_speed_changed(void *priv)
     else
         gus->samp_latch = (uint64_t) (TIMER_USEC * (1000000.0 / gusfreqs[gus->voices - 14]));
 
-#ifdef USE_GUSMAX
     if ((gus->type == GUS_MAX) && (gus->max_ctrl))
         ad1848_speed_changed(&gus->ad1848);
-#endif /*USE_GUSMAX */
 }
 
 static const device_config_t gus_config[] = {
     // clang-format off
-    {
-        .name           = "type",
-        .description    = "GUS type",
-        .type           = CONFIG_SELECTION,
-        .default_string = NULL,
-        .default_int    = 0,
-        .file_filter    = NULL,
-        .spinner        = { 0 },
-        .selection      = {
-            { .description = "Classic", .value = GUS_CLASSIC },
-#ifdef USE_GUSMAX
-            { .description = "MAX",     .value = GUS_MAX     },
-#endif /*USE_GUSMAX */
-            { NULL                                           }
-        },
-        .bios           = { { 0 } }
-    },
     {
         .name           = "base",
         .description    = "Address",
@@ -1502,7 +1461,21 @@ const device_t gus_device = {
     .name          = "Gravis UltraSound",
     .internal_name = "gus",
     .flags         = DEVICE_ISA16,
-    .local         = 0,
+    .local         = GUS_CLASSIC,
+    .init          = gus_init,
+    .close         = gus_close,
+    .reset         = gus_reset,
+    .available     = NULL,
+    .speed_changed = gus_speed_changed,
+    .force_redraw  = NULL,
+    .config        = gus_config
+};
+
+const device_t gus_max_device = {
+    .name          = "Gravis UltraSound MAX",
+    .internal_name = "gus",
+    .flags         = DEVICE_ISA16,
+    .local         = GUS_MAX,
     .init          = gus_init,
     .close         = gus_close,
     .reset         = gus_reset,
diff --git a/src/sound/snd_mmb.c b/src/sound/snd_mmb.c
new file mode 100644
index 000000000..35a72efbc
--- /dev/null
+++ b/src/sound/snd_mmb.c
@@ -0,0 +1,339 @@
+/*
+ * 86Box    A hypervisor and IBM PC system emulator that specializes in
+ *          running old operating systems and software designed for IBM
+ *          PC systems and compatibles from 1981 through fairly recent
+ *          system designs based on the PCI bus.
+ *
+ *          This file is part of the 86Box distribution.
+ *
+ *          Mindscape Music Board emulation.
+ *
+ * Authors: Roy Baer, <https://pcem-emulator.co.uk/>
+ *          Jasmine Iwanek, <jriwanek@gmail.com>
+ *
+ *          Copyright 2025 Roy Baer.
+ *          Copyright 2025 Jasmine Iwanek.
+ */
+#include <stdarg.h>
+#include <stdint.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#define HAVE_STDARG_H
+#include <86box/86box.h>
+#include <86box/device.h>
+#include <86box/io.h>
+#include <86box/sound.h>
+//#i nclude "cpu.h"
+#include "ayumi/ayumi.h"
+#include <86box/snd_mmb.h>
+#include <86box/plat_unused.h>
+
+#ifdef ENABLE_MMB_LOG
+int mmb_do_log = ENABLE_MMB_LOG;
+
+static void
+mmb_log(const char *fmt, ...)
+{
+    va_list ap;
+
+    if (mmb_do_log) {
+        va_start(ap, fmt);
+        pclog_ex(fmt, ap);
+        va_end(ap);
+    }
+}
+#else
+#    define mmb_log(fmt, ...)
+#endif
+
+void
+mmb_update(mmb_t *mmb)
+{
+    for (; mmb->pos < sound_pos_global; mmb->pos++) {
+        ayumi_process(&mmb->first.chip);
+        ayumi_process(&mmb->second.chip);
+
+        ayumi_remove_dc(&mmb->first.chip);
+        ayumi_remove_dc(&mmb->second.chip);
+
+        mmb->buffer[mmb->pos << 1]       = (mmb->first.chip.left + mmb->second.chip.left) * 16000;
+        mmb->buffer[(mmb->pos << 1) + 1] = (mmb->first.chip.right + mmb->second.chip.right) * 16000;
+    }
+}
+
+void
+mmb_get_buffer(int32_t *buffer, int len, void *priv)
+{
+    mmb_t *mmb = (mmb_t *) priv;
+
+    mmb_update(mmb);
+
+    for (int c = 0; c < len * 2; c++)
+        buffer[c] += mmb->buffer[c];
+
+    mmb->pos = 0;
+}
+
+void
+mmb_write(uint16_t addr, uint8_t val, void *priv)
+{
+    mmb_t *mmb = (mmb_t *) priv;
+
+    mmb_update(mmb);
+
+    mmb_log("mmb_write(%04X): activity now: %02X\n", addr, val);
+
+    switch (addr & 3) {
+        case 0:
+            mmb->first.index = val;
+            break;
+        case 2:
+            mmb->second.index = val;
+            break;
+        case 1:
+        case 3:
+            {
+                ay_3_891x_t *ay = ((addr & 2) == 0) ? &mmb->first : &mmb->second;
+
+                switch (ay->index) {
+                    case 0:
+                        ay->regs[0] = val;
+                        ayumi_set_tone(&ay->chip, 0, (ay->regs[1] << 8) | ay->regs[0]);
+                        break;
+                    case 1:
+                        ay->regs[1] = val & 0xf;
+                        ayumi_set_tone(&ay->chip, 0, (ay->regs[1] << 8) | ay->regs[0]);
+                        break;
+                    case 2:
+                        ay->regs[2] = val;
+                        ayumi_set_tone(&ay->chip, 1, (ay->regs[3] << 8) | ay->regs[2]);
+                        break;
+                    case 3:
+                        ay->regs[3] = val & 0xf;
+                        ayumi_set_tone(&ay->chip, 1, (ay->regs[3] << 8) | ay->regs[2]);
+                        break;
+                    case 4:
+                        ay->regs[4] = val;
+                        ayumi_set_tone(&ay->chip, 2, (ay->regs[5] << 8) | ay->regs[4]);
+                        break;
+                    case 5:
+                        ay->regs[5] = val & 0xf;
+                        ayumi_set_tone(&ay->chip, 2, (ay->regs[5] << 8) | ay->regs[4]);
+                        break;
+                    case 6:
+                        ay->regs[6] = val & 0x1f;
+                        ayumi_set_noise(&ay->chip, ay->regs[6]);
+                        break;
+                    case 7:
+                        ay->regs[7] = val;
+                        ayumi_set_mixer(&ay->chip, 0, val & 1, (val >> 3) & 1, (ay->regs[8] >> 4) & 1);
+                        ayumi_set_mixer(&ay->chip, 1, (val >> 1) & 1, (val >> 4) & 1, (ay->regs[9] >> 4) & 1);
+                        ayumi_set_mixer(&ay->chip, 2, (val >> 2) & 1, (val >> 5) & 1, (ay->regs[10] >> 4) & 1);
+                        break;
+                    case 8:
+                        ay->regs[8] = val;
+                        ayumi_set_volume(&ay->chip, 0, val & 0xf);
+                        ayumi_set_mixer(&ay->chip, 0, ay->regs[7] & 1, (ay->regs[7] >> 3) & 1, (val >> 4) & 1);
+                        break;
+                    case 9:
+                        ay->regs[9] = val;
+                        ayumi_set_volume(&ay->chip, 1, val & 0xf);
+                        ayumi_set_mixer(&ay->chip, 1, (ay->regs[7] >> 1) & 1, (ay->regs[7] >> 4) & 1, (val >> 4) & 1);
+                        break;
+                    case 10:
+                        ay->regs[10] = val;
+                        ayumi_set_volume(&ay->chip, 2, val & 0xf);
+                        ayumi_set_mixer(&ay->chip, 2, (ay->regs[7] >> 2) & 1, (ay->regs[7] >> 5) & 1, (val >> 4) & 1);
+                        break;
+                    case 11:
+                        ay->regs[11] = val;
+                        ayumi_set_envelope(&ay->chip, (ay->regs[12] >> 8) | ay->regs[11]);
+                        break;
+                    case 12:
+                        ay->regs[12] = val;
+                        ayumi_set_envelope(&ay->chip, (ay->regs[12] >> 8) | ay->regs[11]);
+                        break;
+                    case 13:
+                        ay->regs[13] = val;
+                        ayumi_set_envelope_shape(&ay->chip, val & 0xf);
+                        break;
+                    case 14:
+                        ay->regs[14] = val;
+                        break;
+                    case 15:
+                        ay->regs[15] = val;
+                        break;
+
+                    default:
+                        break;
+                }
+                break;
+            }
+
+        default:
+            break;
+    }
+}
+
+uint8_t
+mmb_read(uint16_t addr, void *priv)
+{
+    mmb_t       *mmb = (mmb_t *) priv;
+    ay_3_891x_t *ay  = ((addr & 2) == 0) ? &mmb->first : &mmb->second;
+    uint8_t      ret = 0;
+
+    switch (ay->index) {
+        case 0:
+        case 1:
+        case 2:
+        case 3:
+        case 4:
+        case 5:
+        case 6:
+        case 7:
+        case 8:
+        case 9:
+        case 10:
+        case 11:
+        case 12:
+        case 13:
+            ret = ay->regs[ay->index];
+            break;
+        case 14:
+            if (ay->regs[7] & 0x40)
+                ret = ay->regs[14];
+            break;
+        case 15:
+            if (ay->regs[7] & 0x80)
+                ret = ay->regs[15];
+            break;
+
+        default:
+            break;
+    }
+
+    mmb_log("mmb_read(%04X): activity now: %02X\n", addr, ret);
+
+    return ret;
+}
+
+void *
+mmb_init(UNUSED(const device_t *info))
+{
+    mmb_t   *mmb  = calloc(1, sizeof(mmb_t));
+# if 0
+    uint16_t addr = (device_get_config_int("addr96") << 6) | (device_get_config_int("addr52") << 2);
+#else
+    uint16_t addr = 0x300;
+
+#endif
+    sound_add_handler(mmb_get_buffer, mmb);
+
+    ayumi_configure(&mmb->first.chip, 0, MMB_CLOCK, MMB_FREQ);
+    ayumi_configure(&mmb->second.chip, 0, MMB_CLOCK, MMB_FREQ);
+
+    for (uint8_t i = 0; i < 3; i++) {
+        ayumi_set_pan(&mmb->first.chip, i, 0.5, 1);
+        ayumi_set_pan(&mmb->second.chip, i, 0.5, 1);
+    }
+
+    io_sethandler(addr, 0x0004,
+                  mmb_read, NULL, NULL,
+                  mmb_write, NULL, NULL,
+                  mmb);
+
+    return mmb;
+}
+
+void
+mmb_close(void *priv)
+{
+    mmb_t *mmb = (mmb_t *) priv;
+
+    free(mmb);
+}
+
+// clang-format off
+#if 0
+static device_config_t mmb_config[] = {
+    {
+        .name           = "addr96",
+        .description    = "Base address A9...A6",
+        .type           = CONFIG_SELECTION,
+        .default_string = NULL,
+        .default_int    = 12,
+        .file_filter    = NULL,
+        .spinner        = { 0 },
+        .selection   = {
+            { .description = "0000", .value =  0 },
+            { .description = "0001", .value =  1 },
+            { .description = "0010", .value =  2 },
+            { .description = "0011", .value =  3 },
+            { .description = "0100", .value =  4 },
+            { .description = "0101", .value =  5 },
+            { .description = "0110", .value =  6 },
+            { .description = "0111", .value =  7 },
+            { .description = "1000", .value =  8 },
+            { .description = "1001", .value =  9 },
+            { .description = "1010", .value = 10 },
+            { .description = "1011", .value = 11 },
+            { .description = "1100", .value = 12 },
+            { .description = "1101", .value = 13 },
+            { .description = "1110", .value = 14 },
+            { .description = "1111", .value = 15 },
+            { .description = ""                  }
+        },
+        .bios           = { { 0 } }
+    },
+    {
+        .name           = "addr52",
+        .description    = "Base address A5...A2",
+        .type           = CONFIG_SELECTION,
+        .default_string = NULL,
+        .default_int    = 0,
+        .file_filter    = NULL,
+        .spinner        = { 0 },
+        .selection   = {
+            { .description = "0000", .value =  0 },
+            { .description = "0001", .value =  1 },
+            { .description = "0010", .value =  2 },
+            { .description = "0011", .value =  3 },
+            { .description = "0100", .value =  4 },
+            { .description = "0101", .value =  5 },
+            { .description = "0110", .value =  6 },
+            { .description = "0111", .value =  7 },
+            { .description = "1000", .value =  8 },
+            { .description = "1001", .value =  9 },
+            { .description = "1010", .value = 10 },
+            { .description = "1011", .value = 11 },
+            { .description = "1100", .value = 12 },
+            { .description = "1101", .value = 13 },
+            { .description = "1110", .value = 14 },
+            { .description = "1111", .value = 15 },
+            { .description = ""                  }
+        },
+        .bios           = { { 0 } }
+    },
+    { .type = CONFIG_END }
+};
+#endif
+// clang-format on
+
+const device_t mmb_device = {
+    .name          = "Mindscape Music Board",
+    .internal_name = "mmb",
+    .flags         = DEVICE_ISA,
+    .local         = 0,
+    .init          = mmb_init,
+    .close         = mmb_close,
+    .reset         = NULL,
+    .available     = NULL,
+    .speed_changed = NULL,
+    .force_redraw  = NULL,
+#if 0
+    .config        = mmb_config
+#else
+    .config        = NULL
+#endif
+};
diff --git a/src/sound/sound.c b/src/sound/sound.c
index 0c8dffe12..7bf27a136 100644
--- a/src/sound/sound.c
+++ b/src/sound/sound.c
@@ -115,6 +115,7 @@ static const SOUND_CARD sound_cards[] = {
     { &ess_ess0102_pnp_device       },
     { &ess_ess0968_pnp_device       },
     { &gus_device                   },
+    { &gus_max_device               },
     { &sb_1_device                  },
     { &sb_15_device                 },
     { &sb_2_device                  },
@@ -137,6 +138,7 @@ static const SOUND_CARD sound_cards[] = {
     { &sb_vibra16xv_device          },
     { &ssi2001_device               },
     { &entertainer_device           },
+    { &mmb_device                   },
     { &pasplus_device               },
     { &pas16_device                 },
     { &pas16d_device                },
diff --git a/src/video/vid_cl54xx.c b/src/video/vid_cl54xx.c
index 13f96501c..0d02c10c3 100644
--- a/src/video/vid_cl54xx.c
+++ b/src/video/vid_cl54xx.c
@@ -4247,7 +4247,10 @@ gd54xx_init(const device_t *info)
             break;
 
         case CIRRUS_ID_CLGD5420:
-            romfn = BIOS_GD5420_PATH;
+            if (info->local & 0x200)
+                romfn = NULL;
+            else
+                romfn = BIOS_GD5420_PATH;
             break;
 
         case CIRRUS_ID_CLGD5422:
@@ -4978,6 +4981,20 @@ const device_t gd5420_isa_device = {
     .config        = gd542x_config,
 };
 
+const device_t gd5420_onboard_device = {
+    .name          = "Cirrus Logic GD5420 (ISA)",
+    .internal_name = "cl_gd5420_isa",
+    .flags         = DEVICE_ISA16,
+    .local         = CIRRUS_ID_CLGD5420 | 0x200,
+    .init          = gd54xx_init,
+    .close         = gd54xx_close,
+    .reset         = gd54xx_reset,
+    .available     = NULL,
+    .speed_changed = gd54xx_speed_changed,
+    .force_redraw  = gd54xx_force_redraw,
+    .config        = gd542x_config,
+};
+
 const device_t gd5422_isa_device = {
     .name          = "Cirrus Logic GD5422 (ISA)",
     .internal_name = "cl_gd5422_isa",
diff --git a/src/video/vid_hercules.c b/src/video/vid_hercules.c
index 00374d08f..af8ad08f8 100644
--- a/src/video/vid_hercules.c
+++ b/src/video/vid_hercules.c
@@ -543,14 +543,33 @@ hercules_init(UNUSED(const device_t *info))
 
     dev->vram = (uint8_t *) malloc(0x10000);
 
+    switch(device_get_config_int("font")) {
+        case 0:
+            loadfont(FONT_IBM_MDA_437_PATH, 0);
+            break;
+        case 1:
+            loadfont(FONT_IBM_MDA_437_NORDIC_PATH, 0);
+            break;
+        case 2:
+            loadfont(FONT_KAM_PATH, 0);
+            break;
+        case 3:
+            loadfont(FONT_KAMCL16_PATH, 0);
+            break;
+    }
+
     timer_add(&dev->timer, hercules_poll, dev, 1);
 
     mem_mapping_add(&dev->mapping, 0xb0000, 0x08000,
-                    hercules_read, NULL, NULL, hercules_write, NULL, NULL,
-                    NULL /*dev->vram*/, MEM_MAPPING_EXTERNAL, dev);
+                    hercules_read, NULL, NULL,
+                    hercules_write, NULL, NULL,
+                    NULL /*dev->vram*/, MEM_MAPPING_EXTERNAL,
+                    dev);
 
-    io_sethandler(0x03b0, 16,
-                  hercules_in, NULL, NULL, hercules_out, NULL, NULL, dev);
+    io_sethandler(0x03b0, 0x0010,
+                  hercules_in, NULL, NULL,
+                  hercules_out, NULL, NULL,
+                  dev);
 
     for (uint16_t c = 0; c < 256; c++) {
         dev->cols[c][0][0] = dev->cols[c][1][0] = dev->cols[c][1][1] = 16;
@@ -642,6 +661,23 @@ static const device_config_t hercules_config[] = {
         .selection      = { { 0 } },
         .bios           = { { 0 } }
     },
+    {
+        .name           = "font",
+        .description    = "Font",
+        .type           = CONFIG_SELECTION,
+        .default_string = NULL,
+        .default_int    = 0,
+        .file_filter    = NULL,
+        .spinner        = { 0 },
+        .selection      = {
+            { .description = "US (CP 437)",                 .value = 0 },
+            { .description = "IBM Nordic (CP 437-Nordic)",  .value = 1 },
+            { .description = "Czech Kamenicky (CP 895) #1", .value = 2 },
+            { .description = "Czech Kamenicky (CP 895) #2", .value = 3 },
+            { .description = ""                                        }
+        },
+        .bios           = { { 0 } }
+    },
     { .name = "", .description = "", .type = CONFIG_END }
   // clang-format on
 };
diff --git a/src/video/vid_mda.c b/src/video/vid_mda.c
index 66a0fbb71..7b6e54806 100644
--- a/src/video/vid_mda.c
+++ b/src/video/vid_mda.c
@@ -317,8 +317,32 @@ mda_standalone_init(UNUSED(const device_t *info))
 
     mda->vram = malloc(0x1000);
 
-    mem_mapping_add(&mda->mapping, 0xb0000, 0x08000, mda_read, NULL, NULL, mda_write, NULL, NULL, NULL, MEM_MAPPING_EXTERNAL, mda);
-    io_sethandler(0x03b0, 0x0010, mda_in, NULL, NULL, mda_out, NULL, NULL, mda);
+    switch(device_get_config_int("font")) {
+        case 0:
+            loadfont(FONT_IBM_MDA_437_PATH, 0);
+            break;
+        case 1:
+            loadfont(FONT_IBM_MDA_437_NORDIC_PATH, 0);
+            break;
+
+        case 2:
+            loadfont(FONT_KAM_PATH, 0);
+            break;
+        case 3:
+            loadfont(FONT_KAMCL16_PATH, 0);
+            break;
+    }
+
+    mem_mapping_add(&mda->mapping, 0xb0000, 0x08000,
+                    mda_read, NULL, NULL,
+                    mda_write, NULL, NULL,
+                    NULL, MEM_MAPPING_EXTERNAL,
+                    mda);
+
+    io_sethandler(0x03b0, 0x0010,
+                  mda_in, NULL, NULL,
+                  mda_out, NULL, NULL,
+                  mda);
 
     mda_init(mda);
 
@@ -369,6 +393,23 @@ static const device_config_t mda_config[] = {
         },
         .bios           = { { 0 } }
     },
+    {
+        .name           = "font",
+        .description    = "Font",
+        .type           = CONFIG_SELECTION,
+        .default_string = NULL,
+        .default_int    = 0,
+        .file_filter    = NULL,
+        .spinner        = { 0 },
+        .selection      = {
+            { .description = "US (CP 437)",                 .value = 0 },
+            { .description = "IBM Nordic (CP 437-Nordic)",  .value = 1 },
+            { .description = "Czech Kamenicky (CP 895) #1", .value = 2 },
+            { .description = "Czech Kamenicky (CP 895) #2", .value = 3 },
+            { .description = ""                                        }
+        },
+        .bios           = { { 0 } }
+    },
     { .name = "", .description = "", .type = CONFIG_END }
   // clang-format on
 };
diff --git a/src/video/vid_table.c b/src/video/vid_table.c
index e7623392a..a99690cf7 100644
--- a/src/video/vid_table.c
+++ b/src/video/vid_table.c
@@ -332,7 +332,7 @@ video_reset(int card)
                   card, machine_has_flags(machine, MACHINE_VIDEO) ? 1 : 0);
 
     monitor_index_global = 0;
-    loadfont("roms/video/mda/mda.rom", 0);
+    loadfont(FONT_IBM_MDA_437_PATH, 0);
 
     for (uint8_t i = 1; i < GFXCARD_MAX; i ++) {
         if ((card != VID_NONE) && !machine_has_flags(machine, MACHINE_VIDEO_ONLY) &&
diff --git a/src/video/video.c b/src/video/video.c
index 0773e61ce..11edbc3f4 100644
--- a/src/video/video.c
+++ b/src/video/video.c
@@ -1006,76 +1006,73 @@ video_force_resize_set_monitor(uint8_t res, int monitor_index)
 }
 
 void
-loadfont_common(FILE *f, int format)
+loadfont_common(FILE *fp, int format)
 {
-    int c;
-    int d;
-
     switch (format) {
         case 0: /* MDA */
-            for (c = 0; c < 256; c++)
-                for (d = 0; d < 8; d++)
-                    fontdatm[c][d] = fgetc(f) & 0xff;
-            for (c = 0; c < 256; c++)
-                for (d = 0; d < 8; d++)
-                    fontdatm[c][d + 8] = fgetc(f) & 0xff;
-            (void) fseek(f, 4096 + 2048, SEEK_SET);
-            for (c = 0; c < 256; c++)
-                for (d = 0; d < 8; d++)
-                    fontdat[c][d] = fgetc(f) & 0xff;
+            for (uint16_t c = 0; c < 256; c++) /* 8x14 MDA in 8x8 cell (lines 0-7) */
+                for (uint8_t d = 0; d < 8; d++)
+                    fontdatm[c][d] = fgetc(fp) & 0xff;
+            for (uint16_t c = 0; c < 256; c++) /* 8x14 MDA in 8x8 cell (lines 8-13 + padding lines) */
+                for (uint8_t d = 0; d < 8; d++)
+                    fontdatm[c][d + 8] = fgetc(fp) & 0xff;
+            (void) fseek(fp, 4096 + 2048, SEEK_SET);
+            for (uint16_t c = 0; c < 256; c++)
+                for (uint8_t d = 0; d < 8; d++) /* 8x8 CGA (thick, primary) */
+                    fontdat[c][d] = fgetc(fp) & 0xff;
             break;
 
         case 1: /* PC200 */
-            for (d = 0; d < 4; d++) {
+            for (uint8_t d = 0; d < 4; d++) {
                 /* There are 4 fonts in the ROM */
-                for (c = 0; c < 256; c++) /* 8x14 MDA in 8x16 cell */
-                    (void) !fread(&fontdatm[256 * d + c][0], 1, 16, f);
-                for (c = 0; c < 256; c++) { /* 8x8 CGA in 8x16 cell */
-                    (void) !fread(&fontdat[256 * d + c][0], 1, 8, f);
-                    fseek(f, 8, SEEK_CUR);
+                for (uint16_t c = 0; c < 256; c++) /* 8x14 MDA in 8x16 cell */
+                    (void) !fread(&fontdatm[256 * d + c][0], 1, 16, fp);
+                for (uint16_t c = 0; c < 256; c++) { /* 8x8 CGA in 8x16 cell */
+                    (void) !fread(&fontdat[256 * d + c][0], 1, 8, fp);
+                    fseek(fp, 8, SEEK_CUR);
                 }
             }
             break;
 
         default:
         case 2: /* CGA */
-            for (c = 0; c < 256; c++)
-                for (d = 0; d < 8; d++)
-                    fontdat[c][d] = fgetc(f) & 0xff;
+            for (uint16_t c = 0; c < 256; c++)
+                for (uint8_t d = 0; d < 8; d++)
+                    fontdat[c][d] = fgetc(fp) & 0xff;
             break;
 
         case 3: /* Wyse 700 */
-            for (c = 0; c < 512; c++)
-                for (d = 0; d < 32; d++)
-                    fontdatw[c][d] = fgetc(f) & 0xff;
+            for (uint16_t c = 0; c < 512; c++)
+                for (uint8_t d = 0; d < 32; d++)
+                    fontdatw[c][d] = fgetc(fp) & 0xff;
             break;
 
         case 4: /* MDSI Genius */
-            for (c = 0; c < 256; c++)
-                for (d = 0; d < 16; d++)
-                    fontdat8x12[c][d] = fgetc(f) & 0xff;
+            for (uint16_t c = 0; c < 256; c++)
+                for (uint8_t d = 0; d < 16; d++)
+                    fontdat8x12[c][d] = fgetc(fp) & 0xff;
             break;
 
-        case 5:                               /* Toshiba 3100e */
-            for (d = 0; d < 2048; d += 512) { /* Four languages... */
-                for (c = d; c < d + 256; c++) {
-                    (void) !fread(&fontdatm[c][8], 1, 8, f);
+        case 5: /* Toshiba 3100e */
+            for (uint16_t d = 0; d < 2048; d += 512) { /* Four languages... */
+                for (uint16_t c = d; c < d + 256; c++) {
+                    (void) !fread(&fontdatm[c][8], 1, 8, fp);
                 }
-                for (c = d + 256; c < d + 512; c++) {
-                    (void) !fread(&fontdatm[c][8], 1, 8, f);
+                for (uint16_t c = d + 256; c < d + 512; c++) {
+                    (void) !fread(&fontdatm[c][8], 1, 8, fp);
                 }
-                for (c = d; c < d + 256; c++) {
-                    (void) !fread(&fontdatm[c][0], 1, 8, f);
+                for (uint16_t c = d; c < d + 256; c++) {
+                    (void) !fread(&fontdatm[c][0], 1, 8, fp);
                 }
-                for (c = d + 256; c < d + 512; c++) {
-                    (void) !fread(&fontdatm[c][0], 1, 8, f);
+                for (uint16_t c = d + 256; c < d + 512; c++) {
+                    (void) !fread(&fontdatm[c][0], 1, 8, fp);
                 }
-                fseek(f, 4096, SEEK_CUR); /* Skip blank section */
-                for (c = d; c < d + 256; c++) {
-                    (void) !fread(&fontdat[c][0], 1, 8, f);
+                fseek(fp, 4096, SEEK_CUR); /* Skip blank section */
+                for (uint16_t c = d; c < d + 256; c++) {
+                    (void) !fread(&fontdat[c][0], 1, 8, fp);
                 }
-                for (c = d + 256; c < d + 512; c++) {
-                    (void) !fread(&fontdat[c][0], 1, 8, f);
+                for (uint16_t c = d + 256; c < d + 512; c++) {
+                    (void) !fread(&fontdat[c][0], 1, 8, fp);
                 }
             }
             break;
@@ -1087,65 +1084,64 @@ loadfont_common(FILE *f, int format)
             if (!fontdatksc5601_user)
                 fontdatksc5601_user = malloc(192 * sizeof(dbcs_font_t));
 
-            for (c = 0; c < 16384; c++) {
-                for (d = 0; d < 32; d++)
-                    fontdatksc5601[c].chr[d] = fgetc(f) & 0xff;
+            for (uint32_t c = 0; c < 16384; c++) {
+                for (uint8_t d = 0; d < 32; d++)
+                    fontdatksc5601[c].chr[d] = fgetc(fp) & 0xff;
             }
             break;
 
         case 7: /* Sigma Color 400 */
             /* The first 4k of the character ROM holds an 8x8 font */
-            for (c = 0; c < 256; c++) {
-                (void) !fread(&fontdat[c][0], 1, 8, f);
-                fseek(f, 8, SEEK_CUR);
+            for (uint16_t c = 0; c < 256; c++) {
+                (void) !fread(&fontdat[c][0], 1, 8, fp);
+                fseek(fp, 8, SEEK_CUR);
             }
             /* The second 4k holds an 8x16 font */
-            for (c = 0; c < 256; c++) {
-                if (fread(&fontdatm[c][0], 1, 16, f) != 16)
+            for (uint16_t c = 0; c < 256; c++) {
+                if (fread(&fontdatm[c][0], 1, 16, fp) != 16)
                     fatal("loadfont(): Error reading 8x16 font in Sigma Color 400 mode, c = %i\n", c);
             }
             break;
 
-        case 8:                        /* Amstrad PC1512, Toshiba T1000/T1200 */
-            for (c = 0; c < 2048; c++) /* Allow up to 2048 chars */
-                for (d = 0; d < 8; d++)
-                    fontdat[c][d] = fgetc(f) & 0xff;
+        case 8: /* Amstrad PC1512, Toshiba T1000/T1200 */
+            for (uint16_t c = 0; c < 2048; c++) /* Allow up to 2048 chars */
+                for (uint8_t d = 0; d < 8; d++)
+                    fontdat[c][d] = fgetc(fp) & 0xff;
             break;
 
         case 9: /* Image Manager 1024 native font */
-            for (c = 0; c < 256; c++)
-                (void) !fread(&fontdat12x18[c][0], 1, 36, f);
+            for (uint16_t c = 0; c < 256; c++)
+                (void) !fread(&fontdat12x18[c][0], 1, 36, fp);
             break;
 
-        case 10:                       /* Pravetz */
-            for (c = 0; c < 1024; c++) /* Allow up to 1024 chars */
-                for (d = 0; d < 8; d++)
-                    fontdat[c][d] = fgetc(f) & 0xff;
+        case 10: /* Pravetz */
+            for (uint16_t c = 0; c < 1024; c++) /* Allow up to 1024 chars */
+                for (uint8_t d = 0; d < 8; d++)
+                    fontdat[c][d] = fgetc(fp) & 0xff;
             break;
 
-
         case 11: /* PC200 */
-            for (d = 0; d < 4; d++) {
+            for (uint8_t d = 0; d < 4; d++) {
                 /* There are 4 fonts in the ROM */
-                for (c = 0; c < 256; c++) /* 8x14 MDA in 8x16 cell */
-                    (void) !fread(&fontdatm2[256 * d + c][0], 1, 16, f);
-                for (c = 0; c < 256; c++) { /* 8x8 CGA in 8x16 cell */
-                    (void) !fread(&fontdat2[256 * d + c][0], 1, 8, f);
-                    fseek(f, 8, SEEK_CUR);
+                for (uint16_t c = 0; c < 256; c++) /* 8x14 MDA in 8x16 cell */
+                    (void) !fread(&fontdatm2[256 * d + c][0], 1, 16, fp);
+                for (uint16_t c = 0; c < 256; c++) { /* 8x8 CGA in 8x16 cell */
+                    (void) !fread(&fontdat2[256 * d + c][0], 1, 8, fp);
+                    fseek(fp, 8, SEEK_CUR);
                 }
             }
             break;
     }
 
-    (void) fclose(f);
+    (void) fclose(fp);
 }
 
 void
-loadfont_ex(char *s, int format, int offset)
+loadfont_ex(char *fn, int format, int offset)
 {
     FILE *fp;
 
-    fp = rom_fopen(s, "rb");
+    fp = rom_fopen(fn, "rb");
     if (fp == NULL)
         return;
 
@@ -1154,9 +1150,9 @@ loadfont_ex(char *s, int format, int offset)
 }
 
 void
-loadfont(char *s, int format)
+loadfont(char *fn, int format)
 {
-    loadfont_ex(s, format, 0);
+    loadfont_ex(fn, format, 0);
 }
 
 uint32_t