/*
* 86Box A hypervisor and IBM PC system emulator that specializes in
* running old operating systems and software designed for IBM
* PC systems and compatibles from 1981 through fairly recent
* system designs based on the PCI bus.
*
* This file is part of the 86Box distribution.
*
* Emulation of the old and new IBM CGA graphics cards.
*
* Version: @(#)vid_cga.c 1.0.13 2018/01/25
*
* Authors: Sarah Walker,
* Miran Grca,
*
* Copyright 2008-2018 Sarah Walker.
* Copyright 2016-2018 Miran Grca.
*/
#include
#include
#include
#include
#include
#include
#include "../86box.h"
#include "../cpu/cpu.h"
#include "../io.h"
#include "../pit.h"
#include "../mem.h"
#include "../rom.h"
#include "../timer.h"
#include "../device.h"
#include "video.h"
#include "vid_cga.h"
#include "vid_cga_comp.h"
#define CGA_RGB 0
#define CGA_COMPOSITE 1
#define COMPOSITE_OLD 0
#define COMPOSITE_NEW 1
static uint8_t crtcmask[32] =
{
0xff, 0xff, 0xff, 0xff, 0x7f, 0x1f, 0x7f, 0x7f, 0xf3, 0x1f, 0x7f, 0x1f, 0x3f, 0xff, 0x3f, 0xff,
0xff, 0xff, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00
};
void cga_recalctimings(cga_t *cga);
void cga_out(uint16_t addr, uint8_t val, void *p)
{
cga_t *cga = (cga_t *)p;
uint8_t old;
switch (addr)
{
case 0x3D4:
cga->crtcreg = val & 31;
return;
case 0x3D5:
old = cga->crtc[cga->crtcreg];
cga->crtc[cga->crtcreg] = val & crtcmask[cga->crtcreg];
if (old != val)
{
if (cga->crtcreg < 0xe || cga->crtcreg > 0x10)
{
fullchange = changeframecount;
cga_recalctimings(cga);
}
}
return;
case 0x3D8:
if (((cga->cgamode ^ val) & 5) != 0)
{
cga->cgamode = val;
update_cga16_color(cga->cgamode);
}
if ((cga->cgamode ^ val) & 1)
{
cga_palette = (cga->rgb_type << 1);
cgapal_rebuild();
}
cga->cgamode = val;
return;
case 0x3D9:
cga->cgacol = val;
return;
}
}
uint8_t cga_in(uint16_t addr, void *p)
{
cga_t *cga = (cga_t *)p;
switch (addr)
{
case 0x3D4:
return cga->crtcreg;
case 0x3D5:
return cga->crtc[cga->crtcreg];
case 0x3DA:
return cga->cgastat;
}
return 0xFF;
}
void cga_write(uint32_t addr, uint8_t val, void *p)
{
cga_t *cga = (cga_t *)p;
cga->vram[addr & 0x3fff] = val;
if (cga->snow_enabled)
{
cga->charbuffer[ ((int)(((cga->dispontime - cga->vidtime) * 2) / CGACONST)) & 0xfc] = val;
cga->charbuffer[(((int)(((cga->dispontime - cga->vidtime) * 2) / CGACONST)) & 0xfc) | 1] = val;
}
egawrites++;
cycles -= 4;
}
uint8_t cga_read(uint32_t addr, void *p)
{
cga_t *cga = (cga_t *)p;
cycles -= 4;
if (cga->snow_enabled)
{
cga->charbuffer[ ((int)(((cga->dispontime - cga->vidtime) * 2) / CGACONST)) & 0xfc] = cga->vram[addr & 0x3fff];
cga->charbuffer[(((int)(((cga->dispontime - cga->vidtime) * 2) / CGACONST)) & 0xfc) | 1] = cga->vram[addr & 0x3fff];
}
egareads++;
return cga->vram[addr & 0x3fff];
}
void cga_recalctimings(cga_t *cga)
{
double disptime;
double _dispontime, _dispofftime;
/* pclog("Recalc - %i %i %i\n", cga->crtc[0], cga->crtc[1], cga->cgamode & 1); */
if (cga->cgamode & 1)
{
disptime = (double) (cga->crtc[0] + 1);
_dispontime = (double) cga->crtc[1];
}
else
{
disptime = (double) ((cga->crtc[0] + 1) << 1);
_dispontime = (double) (cga->crtc[1] << 1);
}
_dispofftime = disptime - _dispontime;
_dispontime = _dispontime * CGACONST;
_dispofftime = _dispofftime * CGACONST;
cga->dispontime = (int64_t)(_dispontime * (1LL << TIMER_SHIFT));
cga->dispofftime = (int64_t)(_dispofftime * (1LL << TIMER_SHIFT));
}
void cga_poll(void *p)
{
cga_t *cga = (cga_t *)p;
uint16_t ca = (cga->crtc[15] | (cga->crtc[14] << 8)) & 0x3fff;
int drawcursor;
int x, c;
int oldvc;
uint8_t chr, attr;
uint16_t dat;
int cols[4];
int col;
int oldsc;
if (!cga->linepos)
{
cga->vidtime += cga->dispofftime;
cga->cgastat |= 1;
cga->linepos = 1;
oldsc = cga->sc;
if ((cga->crtc[8] & 3) == 3)
cga->sc = ((cga->sc << 1) + cga->oddeven) & 7;
if (cga->cgadispon)
{
if (cga->displine < cga->firstline)
{
cga->firstline = cga->displine;
video_wait_for_buffer();
}
cga->lastline = cga->displine;
for (c = 0; c < 8; c++)
{
if ((cga->cgamode & 0x12) == 0x12)
{
buffer->line[cga->displine][c] = 0;
if (cga->cgamode & 1) buffer->line[cga->displine][c + (cga->crtc[1] << 3) + 8] = 0;
else buffer->line[cga->displine][c + (cga->crtc[1] << 4) + 8] = 0;
}
else
{
buffer->line[cga->displine][c] = (cga->cgacol & 15) + 16;
if (cga->cgamode & 1) buffer->line[cga->displine][c + (cga->crtc[1] << 3) + 8] = (cga->cgacol & 15) + 16;
else buffer->line[cga->displine][c + (cga->crtc[1] << 4) + 8] = (cga->cgacol & 15) + 16;
}
}
if (cga->cgamode & 1)
{
for (x = 0; x < cga->crtc[1]; x++)
{
chr = cga->charbuffer[x << 1];
attr = cga->charbuffer[(x << 1) + 1];
drawcursor = ((cga->ma == ca) && cga->con && cga->cursoron);
if (cga->cgamode & 0x20)
{
cols[1] = (attr & 15) + 16;
cols[0] = ((attr >> 4) & 7) + 16;
if ((cga->cgablink & 8) && (attr & 0x80) && !cga->drawcursor)
cols[1] = cols[0];
}
else
{
cols[1] = (attr & 15) + 16;
cols[0] = (attr >> 4) + 16;
}
if (drawcursor)
{
for (c = 0; c < 8; c++)
buffer->line[cga->displine][(x << 3) + c + 8] = cols[(fontdat[chr + cga->fontbase][cga->sc & 7] & (1 << (c ^ 7))) ? 1 : 0] ^ 15;
}
else
{
for (c = 0; c < 8; c++)
buffer->line[cga->displine][(x << 3) + c + 8] = cols[(fontdat[chr + cga->fontbase][cga->sc & 7] & (1 << (c ^ 7))) ? 1 : 0];
}
cga->ma++;
}
}
else if (!(cga->cgamode & 2))
{
for (x = 0; x < cga->crtc[1]; x++)
{
chr = cga->vram[((cga->ma << 1) & 0x3fff)];
attr = cga->vram[(((cga->ma << 1) + 1) & 0x3fff)];
drawcursor = ((cga->ma == ca) && cga->con && cga->cursoron);
if (cga->cgamode & 0x20)
{
cols[1] = (attr & 15) + 16;
cols[0] = ((attr >> 4) & 7) + 16;
if ((cga->cgablink & 8) && (attr & 0x80)) cols[1] = cols[0];
}
else
{
cols[1] = (attr & 15) + 16;
cols[0] = (attr >> 4) + 16;
}
cga->ma++;
if (drawcursor)
{
for (c = 0; c < 8; c++)
buffer->line[cga->displine][(x << 4)+(c << 1) + 8] = buffer->line[cga->displine][(x << 4) + (c << 1) + 1 + 8] = cols[(fontdat[chr + cga->fontbase][cga->sc & 7] & (1 << (c ^ 7))) ? 1 : 0] ^ 15;
}
else
{
for (c = 0; c < 8; c++)
buffer->line[cga->displine][(x << 4) + (c << 1) + 8] = buffer->line[cga->displine][(x << 4) + (c << 1) + 1 + 8] = cols[(fontdat[chr + cga->fontbase][cga->sc & 7] & (1 << (c ^ 7))) ? 1 : 0];
}
}
}
else if (!(cga->cgamode & 16))
{
cols[0] = (cga->cgacol & 15) | 16;
col = (cga->cgacol & 16) ? 24 : 16;
if (cga->cgamode & 4)
{
cols[1] = col | 3;
cols[2] = col | 4;
cols[3] = col | 7;
}
else if (cga->cgacol & 32)
{
cols[1] = col | 3;
cols[2] = col | 5;
cols[3] = col | 7;
}
else
{
cols[1] = col | 2;
cols[2] = col | 4;
cols[3] = col | 6;
}
for (x = 0; x < cga->crtc[1]; x++)
{
dat = (cga->vram[((cga->ma << 1) & 0x1fff) + ((cga->sc & 1) * 0x2000)] << 8) | cga->vram[((cga->ma << 1) & 0x1fff) + ((cga->sc & 1) * 0x2000) + 1];
cga->ma++;
for (c = 0; c < 8; c++)
{
buffer->line[cga->displine][(x << 4) + (c << 1) + 8] =
buffer->line[cga->displine][(x << 4) + (c << 1) + 1 + 8] = cols[dat >> 14];
dat <<= 2;
}
}
}
else
{
cols[0] = 0; cols[1] = (cga->cgacol & 15) + 16;
for (x = 0; x < cga->crtc[1]; x++)
{
dat = (cga->vram[((cga->ma << 1) & 0x1fff) + ((cga->sc & 1) * 0x2000)] << 8) | cga->vram[((cga->ma << 1) & 0x1fff) + ((cga->sc & 1) * 0x2000) + 1];
cga->ma++;
for (c = 0; c < 16; c++)
{
buffer->line[cga->displine][(x << 4) + c + 8] = cols[dat >> 15];
dat <<= 1;
}
}
}
}
else
{
cols[0] = ((cga->cgamode & 0x12) == 0x12) ? 0 : (cga->cgacol & 15) + 16;
if (cga->cgamode & 1) hline(buffer, 0, cga->displine, (cga->crtc[1] << 3) + 16, cols[0]);
else hline(buffer, 0, cga->displine, (cga->crtc[1] << 4) + 16, cols[0]);
}
if (cga->cgamode & 1) x = (cga->crtc[1] << 3) + 16;
else x = (cga->crtc[1] << 4) + 16;
if (cga->composite)
{
for (c = 0; c < x; c++)
buffer32->line[cga->displine][c] = buffer->line[cga->displine][c] & 0xf;
Composite_Process(cga->cgamode, 0, x >> 2, buffer32->line[cga->displine]);
}
cga->sc = oldsc;
if (cga->vc == cga->crtc[7] && !cga->sc)
cga->cgastat |= 8;
cga->displine++;
if (cga->displine >= 360)
cga->displine = 0;
}
else
{
cga->vidtime += cga->dispontime;
cga->linepos = 0;
if (cga->vsynctime)
{
cga->vsynctime--;
if (!cga->vsynctime)
cga->cgastat &= ~8;
}
if (cga->sc == (cga->crtc[11] & 31) || ((cga->crtc[8] & 3) == 3 && cga->sc == ((cga->crtc[11] & 31) >> 1)))
{
cga->con = 0;
cga->coff = 1;
}
if ((cga->crtc[8] & 3) == 3 && cga->sc == (cga->crtc[9] >> 1))
cga->maback = cga->ma;
if (cga->vadj)
{
cga->sc++;
cga->sc &= 31;
cga->ma = cga->maback;
cga->vadj--;
if (!cga->vadj)
{
cga->cgadispon = 1;
cga->ma = cga->maback = (cga->crtc[13] | (cga->crtc[12] << 8)) & 0x3fff;
cga->sc = 0;
}
}
else if (cga->sc == cga->crtc[9])
{
cga->maback = cga->ma;
cga->sc = 0;
oldvc = cga->vc;
cga->vc++;
cga->vc &= 127;
if (cga->vc == cga->crtc[6])
cga->cgadispon = 0;
if (oldvc == cga->crtc[4])
{
cga->vc = 0;
cga->vadj = cga->crtc[5];
if (!cga->vadj) cga->cgadispon = 1;
if (!cga->vadj) cga->ma = cga->maback = (cga->crtc[13] | (cga->crtc[12] << 8)) & 0x3fff;
if ((cga->crtc[10] & 0x60) == 0x20) cga->cursoron = 0;
else cga->cursoron = cga->cgablink & 8;
}
if (cga->vc == cga->crtc[7])
{
cga->cgadispon = 0;
cga->displine = 0;
cga->vsynctime = 16;
if (cga->crtc[7])
{
if (cga->cgamode & 1) x = (cga->crtc[1] << 3) + 16;
else x = (cga->crtc[1] << 4) + 16;
cga->lastline++;
if ((x != xsize) || ((cga->lastline - cga->firstline) != ysize) || video_force_resize_get())
{
xsize = x;
ysize = cga->lastline - cga->firstline;
if (xsize < 64) xsize = 656;
if (ysize < 32) ysize = 200;
set_screen_size(xsize, (ysize << 1) + 16);
if (video_force_resize_get())
video_force_resize_set(0);
}
if (cga->composite)
video_blit_memtoscreen(0, cga->firstline - 4, 0, (cga->lastline - cga->firstline) + 8, xsize, (cga->lastline - cga->firstline) + 8);
else
video_blit_memtoscreen_8(0, cga->firstline - 4, 0, (cga->lastline - cga->firstline) + 8, xsize, (cga->lastline - cga->firstline) + 8);
frames++;
video_res_x = xsize - 16;
video_res_y = ysize;
if (cga->cgamode & 1)
{
video_res_x /= 8;
video_res_y /= cga->crtc[9] + 1;
video_bpp = 0;
}
else if (!(cga->cgamode & 2))
{
video_res_x /= 16;
video_res_y /= cga->crtc[9] + 1;
video_bpp = 0;
}
else if (!(cga->cgamode & 16))
{
video_res_x /= 2;
video_bpp = 2;
}
else
{
video_bpp = 1;
}
}
cga->firstline = 1000;
cga->lastline = 0;
cga->cgablink++;
cga->oddeven ^= 1;
}
}
else
{
cga->sc++;
cga->sc &= 31;
cga->ma = cga->maback;
}
if (cga->cgadispon)
cga->cgastat &= ~1;
if ((cga->sc == (cga->crtc[10] & 31) || ((cga->crtc[8] & 3) == 3 && cga->sc == ((cga->crtc[10] & 31) >> 1))))
cga->con = 1;
if (cga->cgadispon && (cga->cgamode & 1))
{
for (x = 0; x < (cga->crtc[1] << 1); x++)
cga->charbuffer[x] = cga->vram[(((cga->ma << 1) + x) & 0x3fff)];
}
}
}
void cga_init(cga_t *cga)
{
cga->composite = 0;
}
void *cga_standalone_init(device_t *info)
{
int display_type;
cga_t *cga = malloc(sizeof(cga_t));
memset(cga, 0, sizeof(cga_t));
display_type = device_get_config_int("display_type");
cga->composite = (display_type != CGA_RGB);
cga->revision = device_get_config_int("composite_type");
cga->snow_enabled = device_get_config_int("snow_enabled");
cga->vram = malloc(0x4000);
cga_comp_init(cga->revision);
timer_add(cga_poll, &cga->vidtime, TIMER_ALWAYS_ENABLED, cga);
mem_mapping_add(&cga->mapping, 0xb8000, 0x08000, cga_read, NULL, NULL, cga_write, NULL, NULL, NULL, MEM_MAPPING_EXTERNAL, cga);
io_sethandler(0x03d0, 0x0010, cga_in, NULL, NULL, cga_out, NULL, NULL, cga);
overscan_x = overscan_y = 16;
cga->rgb_type = device_get_config_int("rgb_type");
cga_palette = (cga->rgb_type << 1);
cgapal_rebuild();
return cga;
}
void cga_close(void *p)
{
cga_t *cga = (cga_t *)p;
free(cga->vram);
free(cga);
}
void cga_speed_changed(void *p)
{
cga_t *cga = (cga_t *)p;
cga_recalctimings(cga);
}
device_config_t cga_config[] =
{
{
"display_type", "Display type", CONFIG_SELECTION, "", CGA_RGB,
{
{
"RGB", CGA_RGB
},
{
"Composite", CGA_COMPOSITE
},
{
""
}
}
},
{
"composite_type", "Composite type", CONFIG_SELECTION, "", COMPOSITE_OLD,
{
{
"Old", COMPOSITE_OLD
},
{
"New", COMPOSITE_NEW
},
{
""
}
}
},
{
"rgb_type", "RGB type", CONFIG_SELECTION, "", 0,
{
{
"Color", 0
},
{
"Green Monochrome", 1
},
{
"Amber Monochrome", 2
},
{
"Gray Monochrome", 3
},
{
"Color (no brown)", 4
},
{
""
}
}
},
{
"snow_enabled", "Snow emulation", CONFIG_BINARY, "", 1
},
{
"", "", -1
}
};
device_t cga_device =
{
"CGA",
DEVICE_ISA, 0,
cga_standalone_init,
cga_close,
NULL,
NULL,
cga_speed_changed,
NULL,
NULL,
cga_config
};