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slightly better z80 vdp reads

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This commit is contained in:
notaz 2017-10-01 00:59:44 +03:00
parent 12f89605e3
commit 75b84e4b7c
4 changed files with 79 additions and 41 deletions
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79
pico/videoport.c
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@ -563,43 +563,54 @@ PICO_INTERNAL_ASM unsigned int PicoVideoRead(unsigned int a)
return 0;
}
unsigned int PicoVideoRead8(unsigned int a)
unsigned char PicoVideoRead8DataH(void)
{
unsigned int d;
a&=0x1d;
return VideoRead() >> 8;
}
switch (a)
{
case 0: return VideoRead() >> 8;
case 1: return VideoRead() & 0xff;
case 4: // control port/status reg
d = Pico.video.status >> 8;
if (d&1) Pico.video.status&=~0x100; // FIFO no longer full
Pico.video.pending = 0;
elprintf(EL_SR, "SR read (h): %02x @ %06x", d, SekPc);
return d;
case 5:
d = Pico.video.status & 0xff;
//if (PicoOpt&POPT_ALT_RENDERER) d|=0x0020; // sprite collision (Shadow of the Beast)
d |= ((Pico.video.reg[1]&0x40)^0x40) >> 3; // set V-Blank if display is disabled
d |= (Pico.video.pending_ints&0x20)<<2; // V-int pending?
if (SekCyclesDone() - line_base_cycles >= 488-88) d |= 4; // H-Blank
Pico.video.pending = 0;
elprintf(EL_SR, "SR read (l): %02x @ %06x", d, SekPc);
return d;
case 8: // hv counter
elprintf(EL_HVCNT, "vcounter: %02x (%i) @ %06x", Pico.video.v_counter, SekCyclesDone(), SekPc);
return Pico.video.v_counter;
case 9:
d = (SekCyclesDone() - line_base_cycles) & 0x1ff; // FIXME
if (Pico.video.reg[12]&1)
d = hcounts_40[d];
else d = hcounts_32[d];
elprintf(EL_HVCNT, "hcounter: %02x (%i) @ %06x", d, SekCyclesDone(), SekPc);
return d;
}
unsigned char PicoVideoRead8DataL(void)
{
return VideoRead();
}
return 0;
// FIXME: broken mess
unsigned char PicoVideoRead8CtlH(void)
{
u8 d = (u8)(Pico.video.status >> 8);
if (d & 1)
Pico.video.status &= ~0x100; // FIFO no longer full
Pico.video.pending = 0;
elprintf(EL_SR, "SR read (h): %02x @ %06x", d, SekPc);
return d;
}
unsigned char PicoVideoRead8CtlL(void)
{
u8 d = (u8)Pico.video.status;
//if (PicoOpt&POPT_ALT_RENDERER) d|=0x0020; // sprite collision (Shadow of the Beast)
d |= ((Pico.video.reg[1]&0x40)^0x40) >> 3; // set V-Blank if display is disabled
d |= (Pico.video.pending_ints&0x20)<<2; // V-int pending?
if (SekCyclesDone() - line_base_cycles >= 488-88) d |= 4; // H-Blank
Pico.video.pending = 0;
elprintf(EL_SR, "SR read (l): %02x @ %06x", d, SekPc);
return d;
}
unsigned char PicoVideoRead8HV_H(void)
{
elprintf(EL_HVCNT, "vcounter: %02x (%i) @ %06x", Pico.video.v_counter, SekCyclesDone(), SekPc);
return Pico.video.v_counter;
}
// FIXME: broken
unsigned char PicoVideoRead8HV_L(void)
{
u32 d = (SekCyclesDone() - line_base_cycles) & 0x1ff; // FIXME
if (Pico.video.reg[12]&1)
d = hcounts_40[d];
else d = hcounts_32[d];
elprintf(EL_HVCNT, "hcounter: %02x (%i) @ %06x", d, SekCyclesDone(), SekPc);
return d;
}
// vim:shiftwidth=2:ts=2:expandtab