From 168236950f96028d580d407a8fb28c3d134132fd Mon Sep 17 00:00:00 2001
From: pagefault <>
Date: Wed, 12 Jun 2002 15:59:27 +0000
Subject: [PATCH] NMI fix for register 4212

---
 zsnes/src/cpu/regs.inc | 16 +++++++++++++---
 zsnes/src/init.asm     | 15 ---------------
 2 files changed, 13 insertions(+), 18 deletions(-)

diff --git a/zsnes/src/cpu/regs.inc b/zsnes/src/cpu/regs.inc
index 4c675fa2..a509e5fb 100644
--- a/zsnes/src/cpu/regs.inc
+++ b/zsnes/src/cpu/regs.inc
@@ -18,7 +18,7 @@
 
 EXTSYM SFXEnable,regptr,initsfxregsr,initSA1regs,SA1Enable,initSDD1regs
 EXTSYM SPC7110Enable,initSPC7110regs,RTCEnable,RTCReset
-EXTSYM curypos,cycpl,debuggeron,pdh,Reg4212hack
+EXTSYM curypos,cycpl,debuggeron,pdh
 EXTSYM vram
 EXTSYM romispal
 EXTSYM reg1read,spcnumread,spcon
@@ -1253,7 +1253,11 @@ reg4212r:
     cmp byte[debuggeron],1
     je .debugger
     mov bx,[resolutn]
-    sub bx,[Reg4212hack]
+    cmp word[curypos],bx
+    jne .notres
+    cmp byte[nmistatus],2
+    je .vblank
+.notres
     inc bx
     cmp word[curypos],bx
     jb .novbl
@@ -1261,6 +1265,7 @@ reg4212r:
     dec bx
     cmp word[curypos],bx
     jae .novbl
+.vblank
     or al,80h
 ;    jmp .nohblank
 .novbl
@@ -1284,7 +1289,11 @@ debblah2:
     push edx
     mov dh,[pdh]
     mov bx,[resolutn]
-    sub bx,[Reg4212hack]
+    cmp word[curypos],bx
+    jne .notres
+    cmp byte[nmistatus],2
+    je .vblank
+.notres
     inc bx
     cmp word[curypos],bx
     jb .novbl
@@ -1292,6 +1301,7 @@ debblah2:
     dec bx
     cmp word[curypos],bx
     jae .novbl
+.vblank
     or al,80h
 ;    jmp .nohblank
 .novbl
diff --git a/zsnes/src/init.asm b/zsnes/src/init.asm
index 800df408..58d7c60e 100644
--- a/zsnes/src/init.asm
+++ b/zsnes/src/init.asm
@@ -1332,7 +1332,6 @@ NEWSYM numspcvblleft,  dd 0
 NEWSYM spc700idle,     dd 0
 NEWSYM IRQHack,        dw 0
 NEWSYM Offby1line,     db 0
-NEWSYM Reg4212hack,    dd 0
 NEWSYM CacheCheckSkip,     db 0
 NEWSYM HIRQSkip,     db 0
 NEWSYM ClearScreenSkip, db 0
@@ -1464,7 +1463,6 @@ NEWSYM headerhack
     mov byte[hirqmode2],0
     mov byte[ENVDisable],0
     mov byte[MMXSRAMFix],0
-    mov dword[Reg4212hack],0
 
     mov esi,[romdata]
     add esi,07FC0h
@@ -1495,18 +1493,6 @@ NEWSYM headerhack
     mov byte[cycpblt],125
 .nothumangrandprix3
 
-
-    mov esi,[romdata]
-    add esi,07FC0h
-    cmp dword[esi],'Cu-O'
-    jne .notcuonpa
-    cmp dword[esi+4],'n-Pa'
-    jne .notcuonpa
-    cmp dword[esi+8],' SFC'
-    jne .notcuonpa
-    mov dword[Reg4212hack],2
-.notcuonpa
-
     mov esi,[romdata]
     add esi,07FC0h
     cmp dword[esi],'ACCE'
@@ -1822,7 +1808,6 @@ NEWSYM headerhack
     mov byte[opexec358],220
     mov byte[opexec268cph],64
     mov byte[opexec358cph],64
-    mov byte[Reg4212hack],4
 .noromhead3
 
     ; BToad vs DD - 197/192/47/47 -p 120