Files
86Box/src/vid_unk_ramdac.c

97 lines
3.1 KiB
C

/* Copyright holders: Sarah Walker, Tenshi
see COPYING for more details
*/
/*It is unknown exactly what RAMDAC this is
It is possibly a Sierra 1502x
It's addressed by the TLIVESA1 driver for ET4000*/
/* Note by Tenshi: Not possibly, this *IS* a Sierra 1502x. */
#include "ibm.h"
#include "mem.h"
#include "video.h"
#include "vid_svga.h"
#include "vid_unk_ramdac.h"
void unk_ramdac_out(uint16_t addr, uint8_t val, unk_ramdac_t *ramdac, svga_t *svga)
{
// pclog("OUT RAMDAC %04X %02X\n",addr,val);
int oldbpp = 0;
switch (addr)
{
case 0x3C6:
if (ramdac->state == 4)
{
ramdac->state = 0;
if (val == 0xFF) break;
ramdac->ctrl = val;
oldbpp = svga->bpp;
switch ((val&1)|((val&0xC0)>>5))
{
case 0:
svga->bpp = 8;
break;
case 2: case 3:
switch (val & 0x20)
{
case 0x00: svga->bpp = 32; break;
case 0x20: svga->bpp = 24; break;
}
break;
case 4: case 5:
svga->bpp = 15;
break;
case 6:
svga->bpp = 16;
break;
case 7:
switch (val & 4)
{
case 4:
switch (val & 0x20)
{
case 0x00: svga->bpp = 32; break;
case 0x20: svga->bpp = 24; break;
}
break;
case 0: default:
svga->bpp = 16;
break;
}
case 1: default:
break;
}
if (oldbpp != svga->bpp)
{
svga_recalctimings(svga);
}
// pclog("unk_ramdac: set to %02X (b5 = %i) [%02X], %i bpp\n", (val&1)|((val&0xC0)>>5), val & 0x20 ? 1 : 0, val, svga->bpp);
return;
}
ramdac->state = 0;
break;
case 0x3C7: case 0x3C8: case 0x3C9:
ramdac->state = 0;
break;
}
svga_out(addr, val, svga);
}
uint8_t unk_ramdac_in(uint16_t addr, unk_ramdac_t *ramdac, svga_t *svga)
{
// pclog("IN RAMDAC %04X\n",addr);
switch (addr)
{
case 0x3C6:
if (ramdac->state == 4)
{
ramdac->state = 0;
return ramdac->ctrl;
}
ramdac->state++;
break;
case 0x3C7: case 0x3C8: case 0x3C9:
ramdac->state = 0;
break;
}
return svga_in(addr, svga);
}