games/nes: basic audio support, battery backup, bug fixes

[plan9front.git] / sys / src / games / nes / mem.c

diff --git a/sys/src/games/nes/mem.c b/sys/src/games/nes/mem.c
index 5b983ea32fa56e7f5f5ac4c95f026b40b9dbfd62..c7c8b15ad3379d76072f08c672add229aaac957e 100644 (file)
--- a/sys/src/games/nes/mem.c
+++ b/sys/src/games/nes/mem.c
@@ -158,7 +158,7 @@ mmc3(int p, u8int v)
                        else
                                n--;
                        if(n == 0 && en)
-                               irq |= 2;
+                               irq |= IRQMMC;
                        return;
                case SAVE:
                        put8(m);
@@ -204,7 +204,7 @@ mmc3(int p, u8int v)
                break;
        case 0xC000: l = v; break;
        case 0xC001: n = 0; break;
-       case 0xE000: en = 0; irq &= ~2; break;
+       case 0xE000: en = 0; irq &= ~IRQMMC; break;
        case 0xE001: en = 1; break;
        }
        return;
@@ -281,6 +281,7 @@ u8int
 memread(u16int p)
 {
        u8int v;
+       int i;
 
        if(p < 0x2000){
                p &= 0x7FF;
@@ -305,6 +306,16 @@ memread(u16int p)
                        vrambuf = ppuread(ppuv);
                        incvram();
                        return vrambuf;
+               case APUSTATUS:
+                       v = (irq & 3) << 6;
+                       for(i = 0; i < 4; i++){
+                               if(apuctr[i] != 0)
+                                       v |= (1<<i);
+                       }
+                       if(mem[0x4013] != 0)
+                               v |= (1<<4);
+                       irq &= ~IRQFRAME;
+                       return v;
                case 0x4016:
                        if((mem[p] & 1) != 0)
                                return keys & 1;
@@ -325,6 +336,9 @@ memread(u16int p)
 void
 memwrite(u16int p, u8int v)
 {
+       extern u8int apulen[32];
+       int i;
+
        if(p < 0x2000){
                p &= 0x7FF;
        }else if(p < 0x6000){
@@ -365,15 +379,48 @@ memwrite(u16int p, u8int v)
                        ppuwrite(ppuv, v);
                        incvram();
                        return;
+               case 0x4001:
+               case 0x4005:
+                       i = (p & 0xC) >> 2;
+                       apuctr[i+8] |= 0x80;
+                       break;
+               case 0x4003:
+               case 0x4007:
+               case 0x400B:
+               case 0x400F:
+                       i = (p & 0xC) >> 2;
+                       if((mem[APUSTATUS] & (1<<i)) != 0){
+                               apuctr[i] = apulen[v >> 3];
+                               apuctr[i+4] |= 0x80;
+                       }
+                       break;
                case 0x4014:
                        memcpy(oam, mem + (v<<8), sizeof(oam));
                        return;
+               case APUSTATUS:
+                       for(i = 0; i < 4; i++)
+                               if((v & (1<<i)) == 0)
+                                       apuctr[i] = 0;
+                       irq &= ~IRQDMC;
+                       break;
                case 0x4016:
                        if((mem[p] & 1) != 0 && (v & 1) == 0)
                                keylatch = keys;
                        break;
+               case APUFRAME:
+                       apuseq = 0;
+                       if((v & 0x80) != 0)
+                               apuclock = APUDIV;
+                       else
+                               apuclock = 0;
+                       if((v & 0x40) != 0)
+                               irq &= ~IRQFRAME;
+                       break;
                }
-       }else if(p >= 0x8000){
+       }else if(p < 0x8000){
+               if(saveclock == 0)
+                       saveclock = SAVEFREQ;
+       }else{
                if(mapper[map] != nil)
                        mapper[map](p, v);
                return;