diff --git a/src/machine/m_ps2_mca.c b/src/machine/m_ps2_mca.c
index f02dd265a..09241a2b4 100644
--- a/src/machine/m_ps2_mca.c
+++ b/src/machine/m_ps2_mca.c
@@ -99,6 +99,7 @@ static struct ps2_t {
 
     uint8_t mem_pos_regs[8];
     uint8_t mem_2mb_pos_regs[8];
+    uint8_t mem_2mb_pos_cache[1024];
 
     int pending_cache_miss;
 
@@ -1061,6 +1062,111 @@ ps2_mem_expansion_feedb(UNUSED(void *priv))
     return (ps2.mem_pos_regs[2] & 1);
 }
 
+static uint8_t
+ps2_mem_2mb_cache_read(void)
+{
+    uint8_t cache_addr_lo = ps2.mem_2mb_pos_regs[6];
+    uint8_t cache_addr_hi = ps2.mem_2mb_pos_regs[7];
+    uint16_t cache_addr = (cache_addr_hi << 8) | cache_addr_lo;
+
+    ps2_mca_log("ps2_mem_2mb_cache_read: addr=%04x %02x %04x:%04x\n", cache_addr, ps2.mem_2mb_pos_cache[cache_addr & 0x3ff], CS, cpu_state.pc);
+    return ps2.mem_2mb_pos_cache[cache_addr & 0x3ff];
+}
+
+static void
+ps2_mem_2mb_cache_write(uint8_t val)
+{
+    uint8_t cache_addr_lo = ps2.mem_2mb_pos_regs[6];
+    uint8_t cache_addr_hi = ps2.mem_2mb_pos_regs[7];
+    uint16_t cache_addr = (cache_addr_hi << 8) | cache_addr_lo;
+
+    ps2_mca_log("ps2_mem_2mb_cache_write: addr=%04x %02x %04x:%04x\n", cache_addr, val, CS, cpu_state.pc);
+    ps2.mem_2mb_pos_cache[cache_addr & 0x3ff] = val;
+}
+
+static uint8_t
+ps2_mem_2mb_expansion_read(int port, UNUSED(void *priv))
+{
+    if (port == 0x103) 
+        ps2.mem_2mb_pos_regs[3] = ps2_mem_2mb_cache_read();
+    return ps2.mem_2mb_pos_regs[port & 7];
+}
+
+static void
+ps2_mem_2mb_expansion_write(int port, uint8_t val, UNUSED(void *priv))
+{
+    if (port < 0x102)
+        return;
+
+    if (port == 0x103) 
+        ps2_mem_2mb_cache_write(val);
+    else if (port == 0x102)
+        ps2.mem_2mb_pos_regs[2] = (ps2.mem_2mb_pos_regs[2] & 0xfe) | (val & 0x01);
+    else if (port == 0x105)
+        ps2.mem_2mb_pos_regs[5] = (ps2.mem_2mb_pos_regs[2] & 0x01) | (val & 0xfe);
+    else
+        ps2.mem_2mb_pos_regs[port & 7] = val;
+
+    if (ps2.mem_2mb_pos_regs[2] & 1)
+        mem_mapping_enable(&ps2.expansion_mapping);
+    else
+        mem_mapping_disable(&ps2.expansion_mapping);
+}
+
+static uint8_t
+ps2_mem_2mb_expansion_feedb(UNUSED(void *priv))
+{
+    return (ps2.mem_2mb_pos_regs[2] & 1);
+}
+
+static void
+ps2_mca_mem_fefe_init(int start_mb)
+{
+    uint32_t planar_size;
+    uint32_t expansion_start;
+
+    planar_size     = (start_mb - 1) << 20;
+    expansion_start = start_mb << 20;
+
+    mem_mapping_set_addr(&ram_high_mapping, 0x100000, planar_size);
+
+    ps2.mem_2mb_pos_regs[0] = 0xfe;
+    ps2.mem_2mb_pos_regs[1] = 0xfe;
+
+    switch ((mem_size / 1024) - start_mb) {
+        case 0:/*256Kx2 = 11 11 11 10*/
+            ps2.mem_2mb_pos_regs[2] = 0xfe;
+            ps2.mem_2mb_pos_regs[5] = 0xfe;
+            break;
+        case 1:/*256Kx4 = 11 11 10 10*/
+            ps2.mem_2mb_pos_regs[2] = 0xfa;
+            ps2.mem_2mb_pos_regs[5] = 0xfe;
+            break;
+        case 2:/*256Kx8 = 10 10 10 10*/
+            ps2.mem_2mb_pos_regs[2] = 0xaa;
+            ps2.mem_2mb_pos_regs[5] = 0xfe;
+            break;
+
+        default:
+            break;
+    }
+
+    mca_add(ps2_mem_2mb_expansion_read, ps2_mem_2mb_expansion_write, ps2_mem_2mb_expansion_feedb, NULL, NULL);
+    mem_mapping_add(&ps2.expansion_mapping,
+                    expansion_start,
+                    (mem_size - (start_mb << 10)) << 10,
+                    mem_read_ram,
+                    mem_read_ramw,
+                    mem_read_raml,
+                    mem_write_ram,
+                    mem_write_ramw,
+                    mem_write_raml,
+                    &ram[expansion_start],
+                    MEM_MAPPING_INTERNAL,
+                    NULL);
+    mem_mapping_disable(&ps2.expansion_mapping);
+}
+
 static void
 ps2_mca_mem_fffc_init(int start_mb)
 {
@@ -1188,7 +1294,11 @@ ps2_mca_board_model_50_init(void)
 
     if (mem_size > 2048) {
         /* Only 2 MB supported on planar, create a memory expansion card for the rest */
-        ps2_mca_mem_fffc_init(2);
+        if (mem_size > 4096) {
+            ps2_mca_mem_fffc_init(2);
+        } else {
+            ps2_mca_mem_fefe_init(2);
+        }
     }
 
     if (gfxcard[0] == VID_INTERNAL)
@@ -1235,7 +1345,11 @@ ps2_mca_board_model_60_init(void)
 
     if (mem_size > 4096) {
         /* Only 4 MB supported on planar, create a memory expansion card for the rest */
-        ps2_mca_mem_fffc_init(4);
+        if (mem_size > 6144) {
+            ps2_mca_mem_fffc_init(4);
+        } else {
+            ps2_mca_mem_fefe_init(4);
+        }
     }
 
     device_add(&ps2_nvr_55ls_device);