Files
86Box/src/vid_ati68860_ramdac.c

180 lines
6.7 KiB
C

/* Copyright holders: Sarah Walker
see COPYING for more details
*/
/*ATI 68860 RAMDAC emulation (for Mach64)*/
/*
ATI 68860/68880 Truecolor DACs:
REG08 (R/W):
bit 0-? Always 2 ??
REG0A (R/W):
bit 0-? Always 1Dh ??
REG0B (R/W): (GMR ?)
bit 0-7 Mode. 82h: 4bpp, 83h: 8bpp, A0h: 15bpp, A1h: 16bpp, C0h: 24bpp,
E3h: 32bpp (80h for VGA modes ?)
REG0C (R/W): Device Setup Register A
bit 0 Controls 6/8bit DAC. 0: 8bit DAC/LUT, 1: 6bit DAC/LUT
2-3 Depends on Video memory (= VRAM width ?) . 1: Less than 1Mb, 2: 1Mb,
3: > 1Mb
5-6 Always set ?
7 If set can remove "snow" in some cases (A860_Delay_L ?) ??
*/
#include "ibm.h"
#include "mem.h"
#include "video.h"
#include "vid_svga.h"
#include "vid_ati68860_ramdac.h"
#include "vid_svga_render.h"
void ati68860_ramdac_out(uint16_t addr, uint8_t val, ati68860_ramdac_t *ramdac, svga_t *svga)
{
// pclog("ati68860_out : addr %04X val %02X %04X:%04X\n", addr, val, CS,pc);
switch (addr)
{
case 0:
svga_out(0x3c8, val, svga);
break;
case 1:
svga_out(0x3c9, val, svga);
break;
case 2:
svga_out(0x3c6, val, svga);
break;
case 3:
svga_out(0x3c7, val, svga);
break;
default:
ramdac->regs[addr & 0xf] = val;
switch (addr & 0xf)
{
case 0x4:
ramdac->dac_write = val;
ramdac->dac_pos = 0;
break;
case 0x5:
switch (ramdac->dac_pos)
{
case 0:
ramdac->dac_r = val;
ramdac->dac_pos++;
break;
case 1:
ramdac->dac_g = val;
ramdac->dac_pos++;
break;
case 2:
if (ramdac->dac_write > 1)
break;
ramdac->pal[ramdac->dac_write].r = ramdac->dac_r;
ramdac->pal[ramdac->dac_write].g = ramdac->dac_g;
ramdac->pal[ramdac->dac_write].b = val;
if (ramdac->ramdac_type == RAMDAC_8BIT)
ramdac->pallook[ramdac->dac_write] = makecol32(ramdac->pal[ramdac->dac_write].r, ramdac->pal[ramdac->dac_write].g, ramdac->pal[ramdac->dac_write].b);
else
ramdac->pallook[ramdac->dac_write] = makecol32((ramdac->pal[ramdac->dac_write].r & 0x3f) * 4, (ramdac->pal[ramdac->dac_write].g & 0x3f) * 4, (ramdac->pal[ramdac->dac_write].b & 0x3f) * 4);
ramdac->dac_pos = 0;
ramdac->dac_write = (ramdac->dac_write + 1) & 255;
break;
}
break;
case 0xb:
switch (val)
{
case 0x82:
ramdac->render = svga_render_4bpp_highres;
break;
case 0x83:
ramdac->render = svga_render_8bpp_highres;
break;
case 0xa0: case 0xb0:
ramdac->render = svga_render_15bpp_highres;
break;
case 0xa1: case 0xb1:
ramdac->render = svga_render_16bpp_highres;
break;
case 0xc0: case 0xd0:
ramdac->render = svga_render_24bpp_highres;
break;
case 0xe2: case 0xf7:
ramdac->render = svga_render_32bpp_highres;
break;
case 0xe3:
ramdac->render = svga_render_ABGR8888_highres;
break;
case 0xf2:
ramdac->render = svga_render_RGBA8888_highres;
break;
default:
ramdac->render = svga_render_8bpp_highres;
break;
}
break;
case 0xc:
svga_set_ramdac_type(svga, (val & 1) ? RAMDAC_6BIT : RAMDAC_8BIT);
break;
}
break;
}
}
uint8_t ati68860_ramdac_in(uint16_t addr, ati68860_ramdac_t *ramdac, svga_t *svga)
{
uint8_t ret = 0;
switch (addr)
{
case 0:
ret = svga_in(0x3c8, svga);
break;
case 1:
ret = svga_in(0x3c9, svga);
break;
case 2:
ret = svga_in(0x3c6, svga);
break;
case 3:
ret = svga_in(0x3c7, svga);
break;
case 4: case 8:
ret = 2;
break;
case 6: case 0xa:
ret = 0x1d;
break;
case 0xf:
ret = 0xd0;
break;
default:
ret = ramdac->regs[addr & 0xf];
break;
}
// pclog("ati68860_in : addr %04X ret %02X %04X:%04X\n", addr, ret, CS,pc);
return ret;
}
void ati68860_ramdac_init(ati68860_ramdac_t *ramdac)
{
ramdac->render = svga_render_8bpp_highres;
}
void ati68860_set_ramdac_type(ati68860_ramdac_t *ramdac, int type)
{
int c;
if (ramdac->ramdac_type != type)
{
ramdac->ramdac_type = type;
for (c = 0; c < 2; c++)
{
if (ramdac->ramdac_type == RAMDAC_8BIT)
ramdac->pallook[c] = makecol32(ramdac->pal[c].r, ramdac->pal[c].g, ramdac->pal[c].b);
else
ramdac->pallook[c] = makecol32((ramdac->pal[c].r & 0x3f) * 4, (ramdac->pal[c].g & 0x3f) * 4, (ramdac->pal[c].b & 0x3f) * 4);
}
}
}