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86Box/src/vid_hercules.c

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/*Hercules emulation*/
#include <stdlib.h>
#include "ibm.h"
#include "device.h"
#include "mem.h"
#include "timer.h"
#include "video.h"
#include "vid_hercules.h"
typedef struct hercules_t
{
mem_mapping_t mapping;
uint8_t crtc[32];
int crtcreg;
uint8_t ctrl, ctrl2, stat;
int dispontime, dispofftime;
int64_t vidtime;
int firstline, lastline;
int linepos, displine;
int vc, sc;
uint16_t ma, maback;
int con, coff, cursoron;
int dispon, blink;
int vsynctime, vadj;
uint8_t *vram;
} hercules_t;
static int mdacols[256][2][2];
void hercules_recalctimings(hercules_t *hercules);
void hercules_write(uint32_t addr, uint8_t val, void *p);
uint8_t hercules_read(uint32_t addr, void *p);
void hercules_out(uint16_t addr, uint8_t val, void *p)
{
hercules_t *hercules = (hercules_t *)p;
// pclog("Herc out %04X %02X\n",addr,val);
switch (addr)
{
case 0x3b0: case 0x3b2: case 0x3b4: case 0x3b6:
hercules->crtcreg = val & 31;
return;
case 0x3b1: case 0x3b3: case 0x3b5: case 0x3b7:
hercules->crtc[hercules->crtcreg] = val;
if (hercules->crtc[10] == 6 && hercules->crtc[11] == 7) /*Fix for Generic Turbo XT BIOS, which sets up cursor registers wrong*/
{
hercules->crtc[10] = 0xb;
hercules->crtc[11] = 0xc;
}
hercules_recalctimings(hercules);
return;
case 0x3b8:
hercules->ctrl = val;
return;
case 0x3bf:
hercules->ctrl2 = val;
if (val & 2)
mem_mapping_set_addr(&hercules->mapping, 0xb0000, 0x10000);
else
mem_mapping_set_addr(&hercules->mapping, 0xb0000, 0x08000);
return;
}
}
uint8_t hercules_in(uint16_t addr, void *p)
{
hercules_t *hercules = (hercules_t *)p;
// pclog("Herc in %04X %02X %04X:%04X %04X\n",addr,(hercules_stat & 0xF) | ((hercules_stat & 8) << 4),CS,pc,CX);
switch (addr)
{
case 0x3b0: case 0x3b2: case 0x3b4: case 0x3b6:
return hercules->crtcreg;
case 0x3b1: case 0x3b3: case 0x3b5: case 0x3b7:
return hercules->crtc[hercules->crtcreg];
case 0x3ba:
return (hercules->stat & 0xf) | ((hercules->stat & 8) << 4);
}
return 0xff;
}
void hercules_write(uint32_t addr, uint8_t val, void *p)
{
hercules_t *hercules = (hercules_t *)p;
egawrites++;
/* Horrible hack, I know, but it's the only way to fix the 440FX BIOS filling the VRAM with garbage until Tom fixes the memory emulation. */
if ((cs == 0xE0000) && (cpu_state.pc == 0xBF2F) && (romset == ROM_440FX)) return;
if ((cs == 0xE0000) && (cpu_state.pc == 0xBF77) && (romset == ROM_440FX)) return;
// pclog("Herc write %08X %02X\n",addr,val);
hercules->vram[addr & 0xffff] = val;
}
uint8_t hercules_read(uint32_t addr, void *p)
{
hercules_t *hercules = (hercules_t *)p;
egareads++;
return hercules->vram[addr & 0xffff];
}
void hercules_recalctimings(hercules_t *hercules)
{
double disptime;
double _dispontime, _dispofftime;
disptime = hercules->crtc[0] + 1;
_dispontime = hercules->crtc[1];
_dispofftime = disptime - _dispontime;
_dispontime *= MDACONST;
_dispofftime *= MDACONST;
hercules->dispontime = (int)(_dispontime * (1 << TIMER_SHIFT));
hercules->dispofftime = (int)(_dispofftime * (1 << TIMER_SHIFT));
}
void hercules_poll(void *p)
{
hercules_t *hercules = (hercules_t *)p;
uint16_t ca = (hercules->crtc[15] | (hercules->crtc[14] << 8)) & 0x3fff;
int drawcursor;
int x, c;
int oldvc;
uint8_t chr, attr;
uint16_t dat;
int cols[4];
int oldsc;
int blink;
if (!hercules->linepos)
{
//pclog("Poll %i %i\n",vc,sc);
hercules->vidtime += hercules->dispofftime;
hercules->stat |= 1;
hercules->linepos = 1;
oldsc = hercules->sc;
if ((hercules->crtc[8] & 3) == 3)
hercules->sc = (hercules->sc << 1) & 7;
if (hercules->dispon)
{
if (hercules->displine < hercules->firstline)
{
hercules->firstline = hercules->displine;
}
hercules->lastline = hercules->displine;
cols[0] = 0;
cols[1] = 7;
if ((hercules->ctrl & 2) && (hercules->ctrl2 & 1))
{
ca = (hercules->sc & 3) * 0x2000;
if ((hercules->ctrl & 0x80) && (hercules->ctrl2 & 2))
ca += 0x8000;
// printf("Draw herc %04X\n",ca);
for (x = 0; x < hercules->crtc[1]; x++)
{
dat = (hercules->vram[((hercules->ma << 1) & 0x1fff) + ca] << 8) | hercules->vram[((hercules->ma << 1) & 0x1fff) + ca + 1];
hercules->ma++;
for (c = 0; c < 16; c++)
buffer->line[hercules->displine][(x << 4) + c] = (dat & (32768 >> c)) ? 7 : 0;
}
}
else
{
for (x = 0; x < hercules->crtc[1]; x++)
{
chr = hercules->vram[(hercules->ma << 1) & 0x3fff];
attr = hercules->vram[((hercules->ma << 1) + 1) & 0x3fff];
drawcursor = ((hercules->ma == ca) && hercules->con && hercules->cursoron);
blink = ((hercules->blink & 16) && (hercules->ctrl & 0x20) && (attr & 0x80) && !drawcursor);
if (hercules->sc == 12 && ((attr & 7) == 1))
{
for (c = 0; c < 9; c++)
buffer->line[hercules->displine][(x * 9) + c] = mdacols[attr][blink][1];
}
else
{
for (c = 0; c < 8; c++)
buffer->line[hercules->displine][(x * 9) + c] = mdacols[attr][blink][(fontdatm[chr][hercules->sc] & (1 << (c ^ 7))) ? 1 : 0];
if ((chr & ~0x1f) == 0xc0) buffer->line[hercules->displine][(x * 9) + 8] = mdacols[attr][blink][fontdatm[chr][hercules->sc] & 1];
else buffer->line[hercules->displine][(x * 9) + 8] = mdacols[attr][blink][0];
}
hercules->ma++;
if (drawcursor)
{
for (c = 0; c < 9; c++)
buffer->line[hercules->displine][(x * 9) + c] ^= mdacols[attr][0][1];
}
}
}
}
hercules->sc = oldsc;
if (hercules->vc == hercules->crtc[7] && !hercules->sc)
{
hercules->stat |= 8;
// printf("VSYNC on %i %i\n",vc,sc);
}
hercules->displine++;
if (hercules->displine >= 500)
hercules->displine = 0;
}
else
{
hercules->vidtime += hercules->dispontime;
if (hercules->dispon)
hercules->stat &= ~1;
hercules->linepos = 0;
if (hercules->vsynctime)
{
hercules->vsynctime--;
if (!hercules->vsynctime)
{
hercules->stat &= ~8;
// printf("VSYNC off %i %i\n",vc,sc);
}
}
if (hercules->sc == (hercules->crtc[11] & 31) || ((hercules->crtc[8] & 3) == 3 && hercules->sc == ((hercules->crtc[11] & 31) >> 1)))
{
hercules->con = 0;
hercules->coff = 1;
}
if (hercules->vadj)
{
hercules->sc++;
hercules->sc &= 31;
hercules->ma = hercules->maback;
hercules->vadj--;
if (!hercules->vadj)
{
hercules->dispon = 1;
hercules->ma = hercules->maback = (hercules->crtc[13] | (hercules->crtc[12] << 8)) & 0x3fff;
hercules->sc = 0;
}
}
else if (hercules->sc == hercules->crtc[9] || ((hercules->crtc[8] & 3) == 3 && hercules->sc == (hercules->crtc[9] >> 1)))
{
hercules->maback = hercules->ma;
hercules->sc = 0;
oldvc = hercules->vc;
hercules->vc++;
hercules->vc &= 127;
if (hercules->vc == hercules->crtc[6])
hercules->dispon = 0;
if (oldvc == hercules->crtc[4])
{
// printf("Display over at %i\n",displine);
hercules->vc = 0;
hercules->vadj = hercules->crtc[5];
if (!hercules->vadj) hercules->dispon=1;
if (!hercules->vadj) hercules->ma = hercules->maback = (hercules->crtc[13] | (hercules->crtc[12] << 8)) & 0x3fff;
if ((hercules->crtc[10] & 0x60) == 0x20) hercules->cursoron = 0;
else hercules->cursoron = hercules->blink & 16;
}
if (hercules->vc == hercules->crtc[7])
{
hercules->dispon = 0;
hercules->displine = 0;
hercules->vsynctime = 16;//(crtcm[3]>>4)+1;
if (hercules->crtc[7])
{
// printf("Lastline %i Firstline %i %i\n",lastline,firstline,lastline-firstline);
if ((hercules->ctrl & 2) && (hercules->ctrl2 & 1)) x = hercules->crtc[1] << 4;
else x = hercules->crtc[1] * 9;
hercules->lastline++;
if (x != xsize || (hercules->lastline - hercules->firstline) != ysize)
{
xsize = x;
ysize = hercules->lastline - hercules->firstline;
// printf("Resize to %i,%i - R1 %i\n",xsize,ysize,crtcm[1]);
if (xsize < 64) xsize = 656;
if (ysize < 32) ysize = 200;
updatewindowsize(xsize, ysize);
}
startblit();
video_blit_memtoscreen_8(0, hercules->firstline, xsize, ysize);
endblit();
frames++;
if ((hercules->ctrl & 2) && (hercules->ctrl2 & 1))
{
video_res_x = hercules->crtc[1] * 16;
video_res_y = hercules->crtc[6] * 4;
video_bpp = 1;
}
else
{
video_res_x = hercules->crtc[1];
video_res_y = hercules->crtc[6];
video_bpp = 0;
}
}
hercules->firstline = 1000;
hercules->lastline = 0;
hercules->blink++;
}
}
else
{
hercules->sc++;
hercules->sc &= 31;
hercules->ma = hercules->maback;
}
if ((hercules->sc == (hercules->crtc[10] & 31) || ((hercules->crtc[8] & 3) == 3 && hercules->sc == ((hercules->crtc[10] & 31) >> 1))))
{
hercules->con = 1;
// printf("Cursor on - %02X %02X %02X\n",crtcm[8],crtcm[10],crtcm[11]);
}
}
}
void *hercules_init()
{
int c;
hercules_t *hercules = malloc(sizeof(hercules_t));
memset(hercules, 0, sizeof(hercules_t));
hercules->vram = malloc(0x10000);
timer_add(hercules_poll, &hercules->vidtime, TIMER_ALWAYS_ENABLED, hercules);
mem_mapping_add(&hercules->mapping, 0xb0000, 0x08000, hercules_read, NULL, NULL, hercules_write, NULL, NULL, NULL, 0, hercules);
io_sethandler(0x03b0, 0x0010, hercules_in, NULL, NULL, hercules_out, NULL, NULL, hercules);
for (c = 0; c < 256; c++)
{
mdacols[c][0][0] = mdacols[c][1][0] = mdacols[c][1][1] = 16;
if (c & 8) mdacols[c][0][1] = 15 + 16;
else mdacols[c][0][1] = 7 + 16;
}
mdacols[0x70][0][1] = 16;
mdacols[0x70][0][0] = mdacols[0x70][1][0] = mdacols[0x70][1][1] = 16 + 15;
mdacols[0xF0][0][1] = 16;
mdacols[0xF0][0][0] = mdacols[0xF0][1][0] = mdacols[0xF0][1][1] = 16 + 15;
mdacols[0x78][0][1] = 16 + 7;
mdacols[0x78][0][0] = mdacols[0x78][1][0] = mdacols[0x78][1][1] = 16 + 15;
mdacols[0xF8][0][1] = 16 + 7;
mdacols[0xF8][0][0] = mdacols[0xF8][1][0] = mdacols[0xF8][1][1] = 16 + 15;
mdacols[0x00][0][1] = mdacols[0x00][1][1] = 16;
mdacols[0x08][0][1] = mdacols[0x08][1][1] = 16;
mdacols[0x80][0][1] = mdacols[0x80][1][1] = 16;
mdacols[0x88][0][1] = mdacols[0x88][1][1] = 16;
overscan_x = overscan_y = 0;
return hercules;
}
void hercules_close(void *p)
{
hercules_t *hercules = (hercules_t *)p;
free(hercules->vram);
free(hercules);
}
void hercules_speed_changed(void *p)
{
hercules_t *hercules = (hercules_t *)p;
hercules_recalctimings(hercules);
}
device_t hercules_device =
{
"Hercules",
0,
hercules_init,
hercules_close,
NULL,
hercules_speed_changed,
NULL,
NULL
};