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Rework video memory handling to cater for open bus and VRAM address wrapping. Fixes more hangs with Trio64 and Windows 95.

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This commit is contained in:
SarahW 2017-10-22 12:41:10 +01:00
commit 39a68d757b
10 changed files with 174 additions and 117 deletions
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25
src/vid_s3.c
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@ -818,7 +818,7 @@ void s3_out(uint16_t addr, uint8_t val, void *p)
s3->ma_ext = (s3->ma_ext & 0x1c) | ((val & 0x30) >> 4);
break;
case 0x32:
svga->vrammask = (val & 0x40) ? 0x3ffff : s3->vram_mask;
svga->vram_display_mask = (val & 0x40) ? 0x3ffff : s3->vram_mask;
break;
case 0x50:
@ -2222,6 +2222,29 @@ static void *s3_init(char *bios_fn, int chip)
s3_hwcursor_draw,
NULL);
svga->decode_mask = (4 << 20) - 1;
switch (vram)
{
case 0: /*512kb*/
svga->vram_mask = (1 << 19) - 1;
svga->vram_max = 2 << 20;
break;
case 1: /*1MB*/
/*VRAM in first MB, mirrored in 2nd MB, 3rd and 4th MBs are open bus*/
svga->vram_mask = (1 << 20) - 1;
svga->vram_max = 2 << 20;
break;
case 2: default: /*2MB*/
/*VRAM in first 2 MB, 3rd and 4th MBs are open bus*/
svga->vram_mask = (2 << 20) - 1;
svga->vram_max = 2 << 20;
break;
case 4: /*4MB*/
svga->vram_mask = (4 << 20) - 1;
svga->vram_max = 4 << 20;
break;
}
if (PCI)
svga->crtc[0x36] = 2 | (3 << 2) | (1 << 4) | (vram_sizes[vram] << 5);
else