Files
86Box/src/vid_tvga.c

393 lines
13 KiB
C

/* Copyright holders: Sarah Walker, SA1988
see COPYING for more details
*/
/*Trident TVGA (8900D) emulation*/
#include <stdlib.h>
#include "ibm.h"
#include "device.h"
#include "io.h"
#include "mem.h"
#include "rom.h"
#include "video.h"
#include "vid_svga.h"
#include "vid_svga_render.h"
#include "vid_tkd8001_ramdac.h"
#include "vid_tvga.h"
typedef struct tvga_t
{
mem_mapping_t linear_mapping;
mem_mapping_t accel_mapping;
svga_t svga;
tkd8001_ramdac_t ramdac;
rom_t bios_rom;
uint8_t tvga_3d8, tvga_3d9;
int oldmode;
uint8_t oldctrl1;
uint8_t oldctrl2, newctrl2;
int vram_size;
uint32_t vram_mask;
} tvga_t;
static uint8_t crtc_mask[0x40] =
{
0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
0x7f, 0xff, 0x3f, 0x7f, 0xff, 0xff, 0xff, 0xff,
0xff, 0xff, 0xff, 0xff, 0x7f, 0xff, 0xff, 0xef,
0xff, 0x00, 0x00, 0x00, 0x00, 0x00, 0xff, 0xff,
0x7f, 0x00, 0x00, 0x2f, 0x00, 0x00, 0x00, 0x03,
0x00, 0x13, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00
};
static void tvga_recalcbanking(tvga_t *tvga);
void tvga_out(uint16_t addr, uint8_t val, void *p)
{
tvga_t *tvga = (tvga_t *)p;
svga_t *svga = &tvga->svga;
uint8_t old;
// pclog("tvga_out : %04X %02X %04X:%04X %i\n", addr, val, CS,pc, svga->bpp);
if (((addr&0xFFF0) == 0x3D0 || (addr&0xFFF0) == 0x3B0) && !(svga->miscout & 1)) addr ^= 0x60;
switch (addr)
{
case 0x3C5:
switch (svga->seqaddr & 0xf)
{
case 0xB:
tvga->oldmode=1;
break;
case 0xC:
if (svga->seqregs[0xe] & 0x80)
svga->seqregs[0xc] = val;
break;
case 0xd:
if (tvga->oldmode)
tvga->oldctrl2 = val;
else
{
tvga->newctrl2 = val;
svga_recalctimings(svga);
}
break;
case 0xE:
if (tvga->oldmode)
tvga->oldctrl1 = val;
else
{
svga->seqregs[0xe] = val ^ 2;
tvga->tvga_3d8 = svga->seqregs[0xe] & 0xf;
tvga_recalcbanking(tvga);
}
return;
}
break;
case 0x3C6: case 0x3C7: case 0x3C8: case 0x3C9:
tkd8001_ramdac_out(addr, val, &tvga->ramdac, svga);
return;
case 0x3CF:
switch (svga->gdcaddr & 15)
{
case 0xE:
svga->gdcreg[0xe] = val ^ 2;
tvga->tvga_3d9 = svga->gdcreg[0xe] & 0xf;
tvga_recalcbanking(tvga);
break;
case 0xF:
svga->gdcreg[0xf] = val;
tvga_recalcbanking(tvga);
break;
}
break;
case 0x3D4:
svga->crtcreg = val & 0x3f;
return;
case 0x3D5:
if ((svga->crtcreg < 7) && (svga->crtc[0x11] & 0x80))
return;
if ((svga->crtcreg == 7) && (svga->crtc[0x11] & 0x80))
val = (svga->crtc[7] & ~0x10) | (val & 0x10);
old = svga->crtc[svga->crtcreg];
val &= crtc_mask[svga->crtcreg];
svga->crtc[svga->crtcreg] = val;
// if (svga->crtcreg != 0xC && svga->crtcreg != 0xE && svga->crtcreg != 0xF) pclog("CRTC R%02X = %02X %04X:%04X\n", svga->crtcreg, val, CS, pc);
if (old != val)
{
if (svga->crtcreg < 0xE || svga->crtcreg > 0x10)
{
svga->fullchange = changeframecount;
svga_recalctimings(svga);
}
}
switch (svga->crtcreg)
{
case 0x1e:
svga->vrammask = (val & 0x80) ? tvga->vram_mask : 0x3ffff;
break;
}
return;
case 0x3D8:
if (svga->gdcreg[0xf] & 4)
{
tvga->tvga_3d8 = val;
tvga_recalcbanking(tvga);
}
return;
case 0x3D9:
if (svga->gdcreg[0xf] & 4)
{
tvga->tvga_3d9 = val;
tvga_recalcbanking(tvga);
}
return;
}
svga_out(addr, val, svga);
}
uint8_t tvga_in(uint16_t addr, void *p)
{
tvga_t *tvga = (tvga_t *)p;
svga_t *svga = &tvga->svga;
// if (addr != 0x3da) pclog("tvga_in : %04X %04X:%04X\n", addr, CS,pc);
if (((addr&0xFFF0) == 0x3D0 || (addr&0xFFF0) == 0x3B0) && !(svga->miscout & 1)) addr ^= 0x60;
switch (addr)
{
case 0x3C5:
if ((svga->seqaddr & 0xf) == 0xb)
{
// printf("Read Trident ID %04X:%04X %04X\n",CS,pc,readmemw(ss,SP));
tvga->oldmode = 0;
return 0x33; /*TVGA8900D*/
}
if ((svga->seqaddr & 0xf) == 0xc)
{
// printf("Read Trident Power Up 1 %04X:%04X %04X\n",CS,pc,readmemw(ss,SP));
// return 0x20; /*2 DRAM banks*/
}
if ((svga->seqaddr & 0xf) == 0xd)
{
if (tvga->oldmode) return tvga->oldctrl2;
return tvga->newctrl2;
}
if ((svga->seqaddr & 0xf) == 0xe)
{
if (tvga->oldmode)
return tvga->oldctrl1;
}
break;
case 0x3C6: case 0x3C7: case 0x3C8: case 0x3C9:
return tkd8001_ramdac_in(addr, &tvga->ramdac, svga);
case 0x3D4:
return svga->crtcreg;
case 0x3D5:
if (svga->crtcreg > 0x18 && svga->crtcreg < 0x1e)
return 0xff;
return svga->crtc[svga->crtcreg];
case 0x3d8:
return tvga->tvga_3d8;
case 0x3d9:
return tvga->tvga_3d9;
}
return svga_in(addr, svga);
}
static void tvga_recalcbanking(tvga_t *tvga)
{
svga_t *svga = &tvga->svga;
svga->write_bank = (tvga->tvga_3d8 & 0x1f) * 65536;
if (svga->gdcreg[0xf] & 1)
svga->read_bank = (tvga->tvga_3d9 & 0x1f) * 65536;
else
svga->read_bank = svga->write_bank;
// pclog("recalcbanking: write_bank=%08x read_bank=%08x GDC[E]=%02x GDC[F]=%02x SEQ[E]=%02x 3d8=%02x 3d9=%02x\n", svga->read_bank, svga->write_bank, svga->gdcreg[0xe], svga->gdcreg[0xf], svga->seqregs[0xe], tvga->tvga_3d8, tvga->tvga_3d9);
}
void tvga_recalctimings(svga_t *svga)
{
tvga_t *tvga = (tvga_t *)svga->p;
if (!svga->rowoffset) svga->rowoffset = 0x100; /*This is the only sensible way I can see this being handled,
given that TVGA8900D has no overflow bits.
Some sort of overflow is required for 320x200x24 and 1024x768x16*/
if (svga->crtc[0x29] & 0x10)
svga->rowoffset += 0x100;
if (svga->bpp == 24)
svga->hdisp = (svga->crtc[1] + 1) * 8;
if ((svga->crtc[0x1e] & 0xA0) == 0xA0) svga->ma_latch |= 0x10000;
if ((svga->crtc[0x27] & 0x01) == 0x01) svga->ma_latch |= 0x20000;
if ((svga->crtc[0x27] & 0x02) == 0x02) svga->ma_latch |= 0x40000;
if (tvga->oldctrl2 & 0x10)
{
svga->rowoffset <<= 1;
svga->ma_latch <<= 1;
}
if (svga->gdcreg[0xf] & 0x08)
{
svga->htotal *= 2;
svga->hdisp *= 2;
svga->hdisp_time *= 2;
}
// svga->interlace = svga->crtc[0x1e] & 4;
if (svga->crtc[0x1e] & 4)
{
svga->rowoffset >>= 1;
svga->vtotal *= 2;
svga->dispend *= 2;
svga->vblankstart *= 2;
svga->vsyncstart *= 2;
svga->split *= 2;
}
switch (((svga->miscout >> 2) & 3) | ((tvga->newctrl2 << 2) & 4))
{
case 2: svga->clock = cpuclock/44900000.0; break;
case 3: svga->clock = cpuclock/36000000.0; break;
case 4: svga->clock = cpuclock/57272000.0; break;
case 5: svga->clock = cpuclock/65000000.0; break;
case 6: svga->clock = cpuclock/50350000.0; break;
case 7: svga->clock = cpuclock/40000000.0; break;
}
if (tvga->oldctrl2 & 0x10)
{
switch (svga->bpp)
{
case 8:
svga->render = svga_render_8bpp_highres;
break;
case 15:
svga->render = svga_render_15bpp_highres;
svga->hdisp /= 2;
break;
case 16:
svga->render = svga_render_16bpp_highres;
svga->hdisp /= 2;
break;
case 24:
svga->render = svga_render_24bpp_highres;
svga->hdisp /= 3;
break;
}
svga->lowres = 0;
}
}
void *tvga8900d_init()
{
tvga_t *tvga = malloc(sizeof(tvga_t));
memset(tvga, 0, sizeof(tvga_t));
tvga->vram_size = device_get_config_int("memory") << 10;
tvga->vram_mask = tvga->vram_size - 1;
rom_init(&tvga->bios_rom, "roms/TRIDENT.BIN", 0xc0000, 0x8000, 0x7fff, 0, MEM_MAPPING_EXTERNAL);
svga_init(&tvga->svga, tvga, tvga->vram_size,
tvga_recalctimings,
tvga_in, tvga_out,
NULL,
NULL);
io_sethandler(0x03c0, 0x0020, tvga_in, NULL, NULL, tvga_out, NULL, NULL, tvga);
return tvga;
}
static int tvga8900d_available()
{
return rom_present("roms/TRIDENT.BIN");
}
void tvga_close(void *p)
{
tvga_t *tvga = (tvga_t *)p;
svga_close(&tvga->svga);
free(tvga);
}
void tvga_speed_changed(void *p)
{
tvga_t *tvga = (tvga_t *)p;
svga_recalctimings(&tvga->svga);
}
void tvga_force_redraw(void *p)
{
tvga_t *tvga = (tvga_t *)p;
tvga->svga.fullchange = changeframecount;
}
void tvga_add_status_info(char *s, int max_len, void *p)
{
tvga_t *tvga = (tvga_t *)p;
svga_add_status_info(s, max_len, &tvga->svga);
}
static device_config_t tvga_config[] =
{
{
.name = "memory",
.description = "Memory size",
.type = CONFIG_SELECTION,
.selection =
{
{
.description = "256 kB",
.value = 256
},
{
.description = "512 kB",
.value = 512
},
{
.description = "1 MB",
.value = 1024
},
/*Chip supports 2mb, but drivers are buggy*/
{
.description = ""
}
},
.default_int = 1024
},
{
.type = -1
}
};
device_t tvga8900d_device =
{
"Trident TVGA 8900D",
0,
tvga8900d_init,
tvga_close,
tvga8900d_available,
tvga_speed_changed,
tvga_force_redraw,
tvga_add_status_info,
tvga_config
};