From 5180646dfdedd892de40f748ec6604589b6f0546 Mon Sep 17 00:00:00 2001
From: OBattler <oubattler@gmail.com>
Date: Tue, 26 Aug 2025 13:07:41 +0200
Subject: [PATCH] AT NVR: The Micronics Spitfire requires registers 0x33 and
 0x34 to be initialized to 0xFF instead of 0x00, fixes #6056.

---
 src/nvr_at.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/src/nvr_at.c b/src/nvr_at.c
index 4deda98be..6853867ec 100644
--- a/src/nvr_at.c
+++ b/src/nvr_at.c
@@ -1212,6 +1212,10 @@ nvr_at_init(const device_t *info)
         nvr_at_inited = 1;
     }
 
+    /* This is a hack but it is required for the machine to boot properly, no idea why. */
+    if (nvr->is_new && !strcmp(machine_get_internal_name(), "spitfire"))
+        nvr->regs[0x33] = nvr->regs[0x34] = 0xff;
+
     return nvr;
 }