ref: feb800ff7c8a8fb615c7b39248c2f68859d0fa86
parent: 46168ec503ec75926366a8f4ab505fd44ef271b7
author: aiju <devnull@localhost>
date: Fri Mar 21 08:57:17 EDT 2014
games/snes: address remapping and irq reset bug fix
--- a/sys/src/games/snes/mem.c
+++ b/sys/src/games/snes/mem.c
@@ -24,6 +24,17 @@
extern void calc7(void);
+static u16int
+vrammap(u16int a)
+{+ switch(reg[0x2115] & 12){+ default: return a << 1;
+ case 4: return a << 1 & 0xfe00 | a << 4 & 0x01f0 | a >> 4 & 0x000e;
+ case 8: return a << 1 & 0xfc00 | a << 4 & 0x03f0 | a >> 5 & 0x000e;
+ case 12: return a << 1 & 0xf800 | a << 4 & 0x07f0 | a >> 6 & 0x000e;
+ }
+}
+
static void
incvram(int i, int r)
{@@ -34,10 +45,8 @@
if((c >> 7) != i)
return;
a = reg[0x2116] | reg[0x2117] << 8;
- if((c & 0x0c) != 0)
- print("address remapping\n"); if(r){- b = a<<1;
+ b = vrammap(a);
vramlatch = vram[b++];
vramlatch |= vram[b] << 8;
}
@@ -254,12 +263,12 @@
v &= 0x7f;
break;
case 0x2118:
- a = reg[0x2116] << 1 | reg[0x2117] << 9;
+ a = vrammap(reg[0x2116] | reg[0x2117] << 8);
vram[a] = v;
incvram(0, 0);
return;
case 0x2119:
- a = reg[0x2116] << 1 | reg[0x2117] << 9;
+ a = vrammap(reg[0x2116] | reg[0x2117] << 8);
vram[a|1] = v;
incvram(1, 0);
return;
@@ -306,6 +315,8 @@
case 0x4200:
if((reg[0x4200] & 0x80) == 0 && (v & 0x80) != 0 && (reg[RDNMI] & 0x80) != 0)
nmi = 2;
+ if((v & (HCNTIRQ|VCNTIRQ)) == 0)
+ irq &= ~IRQPPU;
break;
case 0x4201:
if((reg[0x4201] & 0x80) == 0 && (v & 0x80) != 0)