From 52cb2d472b040bf057f49369a86e0ca4bffa88c6 Mon Sep 17 00:00:00 2001
From: aiju <devnull@localhost>
Date: Fri, 21 Mar 2014 13:57:25 +0100
Subject: [PATCH] games/snes: fixed decimal mode

---
 sys/src/games/snes/cpu.c | 12 ++++++++----
 1 file changed, 8 insertions(+), 4 deletions(-)

diff --git a/sys/src/games/snes/cpu.c b/sys/src/games/snes/cpu.c
index f307028c7..cea3c1d91 100644
--- a/sys/src/games/snes/cpu.c
+++ b/sys/src/games/snes/cpu.c
@@ -357,11 +357,11 @@ adc(u16int a)
 			if(r > 0x0009) r += 0x0006;
 			if(r > 0x001f) r -= 0x0010;
 			r += (rA & 0x00f0) + (a & 0x00f0);
-			if(r > 0x0090) r += 0x0060;
-			if(r > 0x01f0) r -= 0x0100;
+			if(r > 0x009f) r += 0x0060;
+			if(r > 0x01ff) r -= 0x0100;
 			r += (rA & 0x0f00) + (a & 0x0f00);
-			if(r > 0x0900) r += 0x0600;
-			if(r > 0x1f00) r -= 0x1000;
+			if(r > 0x09ff) r += 0x0600;
+			if(r > 0x1fff) r -= 0x1000;
 			r += (rA & 0xf000) + (a & 0xf000);
 		}else
 			r = rA + a + (rP & FLAGC);
@@ -505,6 +505,7 @@ sbc(u16int a)
 		if((rP & FLAGD) != 0){
 			r = (rA & 0xf) + (a & 0xf) + (rP & FLAGC);
 			if(r < 0x10) r -= 0x06;
+			if(r < 0) r += 0x10;
 			r += (rA & 0xf0) + (a & 0xf0);
 		}else
 			r = (rA & 0xff) + a + (rP & FLAGC);
@@ -525,10 +526,13 @@ sbc(u16int a)
 		if((rP & FLAGD) != 0){
 			r  = (rA & 0x000f) + (a & 0x000f) + (rP & FLAGC);
 			if(r < 0x0010) r -= 0x0006;
+			if(r < 0x0000) r += 0x0010;
 			r += (rA & 0x00f0) + (a & 0x00f0);
 			if(r < 0x0100) r -= 0x0060;
+			if(r < 0x0000) r += 0x0100;
 			r += (rA & 0x0f00) + (a & 0x0f00);
 			if(r < 0x1000) r -= 0x0600;
+			if(r < 0x0000) r += 0x1000;
 			r += (rA & 0xf000) + (a & 0xf000);
 		}else
 			r = rA + a + (rP & FLAGC);