Files
86Box/src/vid_ati18800.c

203 lines
5.9 KiB
C

/* Copyright holders: Sarah Walker
see COPYING for more details
*/
/*ATI 18800 emulation (VGA Edge-16)*/
#include <stdlib.h>
#include "ibm.h"
#include "device.h"
#include "io.h"
#include "mem.h"
#include "rom.h"
#include "video.h"
#include "vid_ati18800.h"
#include "vid_ati_eeprom.h"
#include "vid_svga.h"
typedef struct ati18800_t
{
svga_t svga;
ati_eeprom_t eeprom;
rom_t bios_rom;
uint8_t regs[256];
int index;
} ati18800_t;
void ati18800_out(uint16_t addr, uint8_t val, void *p)
{
ati18800_t *ati18800 = (ati18800_t *)p;
svga_t *svga = &ati18800->svga;
uint8_t old;
// pclog("ati18800_out : %04X %02X %04X:%04X\n", addr, val, CS,cpu_state.pc);
if (((addr&0xFFF0) == 0x3D0 || (addr&0xFFF0) == 0x3B0) && !(svga->miscout&1)) addr ^= 0x60;
switch (addr)
{
case 0x1ce:
ati18800->index = val;
break;
case 0x1cf:
ati18800->regs[ati18800->index] = val;
switch (ati18800->index)
{
case 0xb2:
case 0xbe:
if (ati18800->regs[0xbe] & 8) /*Read/write bank mode*/
{
svga->read_bank = ((ati18800->regs[0xb2] >> 5) & 7) * 0x10000;
svga->write_bank = ((ati18800->regs[0xb2] >> 1) & 7) * 0x10000;
}
else /*Single bank mode*/
svga->read_bank = svga->write_bank = ((ati18800->regs[0xb2] >> 1) & 7) * 0x10000;
break;
case 0xb3:
ati_eeprom_write(&ati18800->eeprom, val & 8, val & 2, val & 1);
break;
}
break;
case 0x3D4:
svga->crtcreg = val & 0x3f;
return;
case 0x3D5:
if (svga->crtcreg <= 0x18)
val &= mask_crtc[svga->crtcreg];
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];
svga->crtc[svga->crtcreg] = val;
if (old != val)
{
if (svga->crtcreg < 0xe || svga->crtcreg > 0x10)
{
svga->fullchange = changeframecount;
svga_recalctimings(svga);
}
}
break;
}
svga_out(addr, val, svga);
}
uint8_t ati18800_in(uint16_t addr, void *p)
{
ati18800_t *ati18800 = (ati18800_t *)p;
svga_t *svga = &ati18800->svga;
uint8_t temp;
// if (addr != 0x3da) pclog("ati18800_in : %04X ", addr);
if (((addr&0xFFF0) == 0x3D0 || (addr&0xFFF0) == 0x3B0) && !(svga->miscout&1)) addr ^= 0x60;
switch (addr)
{
case 0x1ce:
temp = ati18800->index;
break;
case 0x1cf:
switch (ati18800->index)
{
case 0xb7:
temp = ati18800->regs[ati18800->index] & ~8;
if (ati_eeprom_read(&ati18800->eeprom))
temp |= 8;
break;
default:
temp = ati18800->regs[ati18800->index];
break;
}
break;
case 0x3D4:
temp = svga->crtcreg;
break;
case 0x3D5:
temp = svga->crtc[svga->crtcreg];
break;
default:
temp = svga_in(addr, svga);
break;
}
#ifndef RELEASE_BUILD
if (addr != 0x3da) pclog("%02X %04X:%04X\n", temp, CS,cpu_state.pc);
#endif
return temp;
}
void *ati18800_init()
{
ati18800_t *ati18800 = malloc(sizeof(ati18800_t));
memset(ati18800, 0, sizeof(ati18800_t));
rom_init(&ati18800->bios_rom, "roms/vgaedge16.vbi", 0xc0000, 0x8000, 0x7fff, 0, MEM_MAPPING_EXTERNAL);
svga_init(&ati18800->svga, ati18800, 1 << 19, /*512kb*/
NULL,
ati18800_in, ati18800_out,
NULL,
NULL);
io_sethandler(0x01ce, 0x0002, ati18800_in, NULL, NULL, ati18800_out, NULL, NULL, ati18800);
io_sethandler(0x03c0, 0x0020, ati18800_in, NULL, NULL, ati18800_out, NULL, NULL, ati18800);
ati18800->svga.miscout = 1;
ati_eeprom_load(&ati18800->eeprom, "ati18800.nvr", 0);
return ati18800;
}
static int ati18800_available()
{
return rom_present("roms/vgaedge16.vbi");
}
void ati18800_close(void *p)
{
ati18800_t *ati18800 = (ati18800_t *)p;
svga_close(&ati18800->svga);
free(ati18800);
}
void ati18800_speed_changed(void *p)
{
ati18800_t *ati18800 = (ati18800_t *)p;
svga_recalctimings(&ati18800->svga);
}
void ati18800_force_redraw(void *p)
{
ati18800_t *ati18800 = (ati18800_t *)p;
ati18800->svga.fullchange = changeframecount;
}
void ati18800_add_status_info(char *s, int max_len, void *p)
{
ati18800_t *ati18800 = (ati18800_t *)p;
svga_add_status_info(s, max_len, &ati18800->svga);
}
device_t ati18800_device =
{
"ATI-18800",
0,
ati18800_init,
ati18800_close,
ati18800_available,
ati18800_speed_changed,
ati18800_force_redraw,
ati18800_add_status_info
};