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[Core/SCD] improved CD drive seek time emulation (fixes Panic!/Switch intro)

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This commit is contained in:
EkeEke 2013-04-28 20:47:52 +02:00
parent 5b33778524
commit c3db7ade7d
1 changed files with 29 additions and 5 deletions
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34
source/cd_hw/cdd.c
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@ -879,10 +879,24 @@ void cdd_update(void)
error("LBA = %d (track n°%d)\n", cdd.lba, cdd.index); error("LBA = %d (track n°%d)\n", cdd.lba, cdd.index);
#endif #endif
/* reading disc */ /* seeking disc */
if (cdd.status == CD_PLAY) if (cdd.status == CD_SEEK)
{ {
/* drive access latency */ /* drive latency */
if (cdd.latency > 0)
{
cdd.latency--;
return;
}
/* drive is ready */
cdd.status = CD_READY;
}
/* reading disc */
else if (cdd.status == CD_PLAY)
{
/* drive latency */
if (cdd.latency > 0) if (cdd.latency > 0)
{ {
cdd.latency--; cdd.latency--;
@ -1216,7 +1230,17 @@ void cdd_process(void)
(scd.regs[0x46>>1].byte.h * 10 + scd.regs[0x46>>1].byte.l)) * 75 + (scd.regs[0x46>>1].byte.h * 10 + scd.regs[0x46>>1].byte.l)) * 75 +
(scd.regs[0x48>>1].byte.h * 10 + scd.regs[0x48>>1].byte.l) - 150; (scd.regs[0x48>>1].byte.h * 10 + scd.regs[0x48>>1].byte.l) - 150;
/* update current LBA (TODO: add some delay ?) */ /* CD drive seek time (required by Switch / Panic intro - see CD_PLAY command for details)*/
if (lba < cdd.lba)
{
cdd.latency = (((cdd.lba - lba) * 120) / 270000);
}
else
{
cdd.latency = (((lba - cdd.lba) * 120) / 270000);
}
/* update current LBA */
cdd.lba = lba; cdd.lba = lba;
/* update current track index */ /* update current track index */
@ -1241,7 +1265,7 @@ void cdd_process(void)
scd.regs[0x36>>1].byte.h = 0x01; scd.regs[0x36>>1].byte.h = 0x01;
/* update status */ /* update status */
cdd.status = CD_READY; cdd.status = CD_SEEK;
scd.regs[0x38>>1].w = CD_SEEK << 8; scd.regs[0x38>>1].w = CD_SEEK << 8;
scd.regs[0x3a>>1].w = 0x0000; scd.regs[0x3a>>1].w = 0x0000;
scd.regs[0x3c>>1].w = 0x0000; scd.regs[0x3c>>1].w = 0x0000;