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sms, improve vdp (read buffer, h counter)

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This commit is contained in:
kub 2021-10-17 22:47:18 +02:00
parent c644ce99cd
commit e4da4fe8b9
1 changed files with 22 additions and 9 deletions
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31
pico/sms.c
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@ -21,13 +21,15 @@ extern void YM2413_dataWrite(unsigned data);
static unsigned short ymflag = 0xffff;
static u8 vdp_buffer;
static unsigned char vdp_data_read(void)
{
struct PicoVideo *pv = &Pico.video;
unsigned char d;
d = PicoMem.vramb[MEM_LE2(pv->addr)];
d = vdp_buffer;
vdp_buffer = PicoMem.vramb[MEM_LE2(pv->addr)];
pv->addr = (pv->addr + 1) & 0x3fff;
pv->pending = 0;
return d;
@ -54,12 +56,14 @@ static void vdp_data_write(unsigned char d)
if (pv->type == 3) {
if (Pico.m.hardware & 0x1) { // GG, same layout as MD
unsigned a = pv->addr & 0x3f;
if (a & 0x1) d &= 0x0f;
if (((u8 *)PicoMem.cram)[MEM_LE2(a)] != d) Pico.m.dirtyPal = 1;
((u8 *)PicoMem.cram)[MEM_LE2(a)] = d;
if (a & 0x1) { // write complete color on high byte write
u16 c = ((d&0x0f) << 8) | vdp_buffer;
if (PicoMem.cram[a >> 1] != c) Pico.m.dirtyPal = 1;
PicoMem.cram[a >> 1] = c;
}
} else { // SMS, convert to MD layout (00BbGgRr to 0000BbBbGgGgRrRr)
unsigned a = pv->addr & 0x1f;
u16 c = (d&0x30)*0x40 + (d&0x0c)*0x10 + (d&0x03)*0x04;
u16 c = ((d&0x30)<<6) + ((d&0x0c)<<4) + ((d&0x03)<<2);
if (PicoMem.cram[a] != (c | (c>>2))) Pico.m.dirtyPal = 1;
PicoMem.cram[a] = c | (c>>2);
}
@ -68,6 +72,7 @@ static void vdp_data_write(unsigned char d)
}
pv->addr = (pv->addr + 1) & 0x3fff;
vdp_buffer = d;
pv->pending = 0;
}
@ -95,14 +100,18 @@ static void vdp_ctl_write(u8 d)
struct PicoVideo *pv = &Pico.video;
if (pv->pending) {
if ((d >> 6) == 2) {
pv->type = d >> 6;
if (pv->type == 2) {
elprintf(EL_IO, " VDP r%02x=%02x", d & 0x0f, pv->addr & 0xff);
if (pv->reg[d & 0x0f] != (u8)pv->addr)
vdp_reg_write(pv, d & 0x0f, pv->addr);
}
pv->type = d >> 6;
pv->addr &= 0x00ff;
pv->addr |= (d & 0x3f) << 8;
if (pv->type == 0) {
vdp_buffer = PicoMem.vramb[MEM_LE2(pv->addr)];
pv->addr = (pv->addr + 1) & 0x3fff;
}
} else {
pv->addr &= 0x3f00;
pv->addr |= d;
@ -147,8 +156,12 @@ static unsigned char z80_sms_in(unsigned short a)
elprintf(EL_HVCNT, "V counter read: %02x", d);
break;
case 0x41: /* H counter */
d = Pico.m.rotate++;
case 0x41: /* H counter, TODO: latched by toggle of pad TH line */
// 171 slots per scanline of 228 clocks, runs from 0x85-0x93,0xe9-0x84
#define CYC2SLOT (256 * 171/228) // cycles to slot factor in Q8
d = 228-z80_cyclesLeft;
if (d <= 19) d = (( d * CYC2SLOT)>>8) + 0x85;
else d = (((d-20) * CYC2SLOT)>>8) + 0xe9;
elprintf(EL_HVCNT, "H counter read: %02x", d);
break;