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igs025/igs022 DMA mode 4 (for drgw3)

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This commit is contained in:
David Haywood 2013-10-06 14:09:10 +00:00
parent a27b932e9d
commit d0cc61a9f6
1 changed files with 24 additions and 14 deletions
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38
src/mame/machine/pgmprot_igs025_igs022.c
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@ -327,7 +327,7 @@ void pgm_022_025_state::IGS022_do_dma(UINT16 src, UINT16 dst, UINT16 size, UINT1
param = mode >> 8;
mode &=0xf; // what are the other bits?
if ((mode == 0) || (mode == 1) || (mode == 2) || (mode == 3))
if ((mode == 0) || (mode == 1) || (mode == 2) || (mode == 3) || (mode == 4))
{
/* mode3 applies a xor from a 0x100 byte table to the data being
transferred
@ -351,27 +351,37 @@ void pgm_022_025_state::IGS022_do_dma(UINT16 src, UINT16 dst, UINT16 size, UINT1
UINT8 taboff = ((x*2)+extraoffset) & 0xff; // must allow for overflow in instances of odd offsets
UINT16 extraxor = ((dectable[taboff+1]) << 8) | (dectable[taboff+0] << 0);
if (mode==4)
{
extraxor = 0;
if ((x & 0x003) == 0x000) extraxor |= 0x0049; // 'I'
if ((x & 0x003) == 0x001) extraxor |= 0x0047; // 'G'
if ((x & 0x003) == 0x002) extraxor |= 0x0053; // 'S'
if ((x & 0x003) == 0x003) extraxor |= 0x0020; // ' '
if ((x & 0x300) == 0x000) extraxor |= 0x4900; // 'I'
if ((x & 0x300) == 0x100) extraxor |= 0x4700; // 'G'
if ((x & 0x300) == 0x200) extraxor |= 0x5300; // 'S'
if ((x & 0x300) == 0x300) extraxor |= 0x2000; // ' '
}
// mode==0 plain
if (mode==3) dat2 ^= extraxor;
if (mode==2) dat2 += extraxor;
if (mode==1) dat2 -= extraxor;
if (mode==4)
{
printf("%06x | %04x (%04x)\n", (dst+x)*2, dat2, (UINT16)(dat2-extraxor));
dat2 -= extraxor;
}
m_sharedprotram[dst + x] = dat2;
}
}
else if (mode == 4)
{
mame_printf_debug("unhandled copy mode %04x!\n", mode);
int x;
for (x = 0; x < size; x++)
{
m_sharedprotram[dst + x] = 0x4e75; // Hack until algorithm for decoding this is figured out.
}
// not used by killing blade
/* looks almost like a fixed value xor, but isn't */
}
else if (mode == 5)
{
/* mode 5 seems to be a straight copy, byteswap */