xfnw/plan9fox
1
0
Fork 0
Code Issues Pull requests Projects Releases Wiki Activity

games/nes: bug fixing

Browse source
This commit is contained in:
aiju 2014-02-20 23:22:14 +01:00
parent 9c40e15ba8
commit eeac553c36
4 changed files with 25 additions and 5 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

15
sys/src/games/nes/cpu.c
View file

@ -6,6 +6,7 @@
u16int pc, curpc;
u8int rA, rX, rY, rS, rP;
int nmi;
extern int map;
static u8int
fetch8(void)
@ -172,7 +173,13 @@ dec(u16int a)
static void
inc(u16int a)
{
memwrite(a, nz(memread(a) + 1));
u8int v;
v = memread(a);
memwrite(a, v);
v = nz(v + 1);
if(!(map == 1 && a >= 0x8000))
memwrite(a, v);
}
static void
@ -229,6 +236,8 @@ interrupt(int nmi, int brk)
rP |= FLAGI;
}
int trace;
int
step(void)
{
@ -243,6 +252,8 @@ step(void)
}
curpc = pc;
op = fetch8();
if(trace)
print("%x %x %x %x %x %x %x %x\n", curpc, op, rA, rX, rY, rS, rP, memread(0x2c));
switch(op){
case 0x00: pc++; interrupt(0, 1); return 7;
case 0x01: nz(rA |= indX()); return 6;
@ -397,12 +408,12 @@ step(void)
case 0xC5: cmp(rA, zp()); return 3;
case 0xC9: cmp(rA, imm()); return 2;
case 0xCD: cmp(rA, abso()); return 4;
case 0xD0: if((rP & FLAGZ) == 0) return branch(); pc++; return 3;
case 0xD1: cmp(rA, indY(&c)); return 5 + c;
case 0xD5: cmp(rA, zpX()); return 4;
case 0xD8: rP &= ~FLAGD; return 2;
case 0xD9: cmp(rA, absY()); return 4 + ((u8int)a < rY);
case 0xDD: cmp(rA, absX()); return 4 + ((u8int)a < rX);
case 0xD0: if((rP & FLAGZ) == 0) return branch(); pc++; return 3;
case 0xC0: cmp(rY, imm()); return 2;
case 0xC4: cmp(rY, zp()); return 3;
case 0xC6: dec(fetch8()); return 5;

3
sys/src/games/nes/mem.c
View file

@ -193,7 +193,8 @@ memwrite(u16int p, u8int v)
p &= 0x2007;
switch(p){
case PPUCTRL:
if((v & PPUNMI) != 0 && (mem[PPUSTATUS] & PPUVBLANK) != 0)
if((mem[PPUCTRL] & PPUNMI) == 0 && (v & PPUNMI) != 0 &&
(mem[PPUSTATUS] & PPUVBLANK) != 0)
nmi = 1;
pput = (pput & 0xF3FF) | ((v & 3) << 10);
break;

4
sys/src/games/nes/nes.c
View file

@ -83,6 +83,8 @@ loadrom(char *file)
mapper[map](-1, 0);
}
extern int trace;
void
keyproc(void *)
{
@ -99,6 +101,8 @@ keyproc(void *)
if(buf[0] == 'c'){
if(utfrune(buf, Kdel))
threadexitsall(nil);
if(utfrune(buf, 't'))
trace ^= 1;
}
if(buf[0] != 'k' && buf[0] != 'K')
continue;

8
sys/src/games/nes/ppu.c
View file

@ -5,7 +5,7 @@
#include "dat.h"
#include "fns.h"
int ppuy, ppux;
int ppuy, ppux, odd;
uchar pic[256*240*4*9];
extern uchar oam[256];
@ -289,7 +289,11 @@ ppustep(void)
if(ppux > 340){
ppux = 0;
ppuy++;
if(ppuy > 261)
if(ppuy > 261){
ppuy = 0;
if(odd && (mem[PPUCTRL] & (BGDISP | SPRITEDISP)) != 0)
ppux++;
odd ^= 1;
}
}
}