Files
86Box/src/video/vid_hercules.c
2023-08-23 00:50:52 -04:00

669 lines
20 KiB
C

/*
* 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.
*
* Hercules emulation.
*
*
*
* Authors: Sarah Walker, <https://pcem-emulator.co.uk/>
* Miran Grca, <mgrca8@gmail.com>
*
* Copyright 2008-2019 Sarah Walker.
* Copyright 2016-2019 Miran Grca.
*/
#include <stdio.h>
#include <stdint.h>
#include <stdlib.h>
#include <string.h>
#include <wchar.h>
#include <86box/86box.h>
#include "cpu.h"
#include <86box/mem.h>
#include <86box/rom.h>
#include <86box/io.h>
#include <86box/timer.h>
#include <86box/lpt.h>
#include <86box/pit.h>
#include <86box/device.h>
#include <86box/video.h>
#include <86box/vid_hercules.h>
#include <86box/plat_unused.h>
static video_timings_t timing_hercules = { .type = VIDEO_ISA, .write_b = 8, .write_w = 16, .write_l = 32, .read_b = 8, .read_w = 16, .read_l = 32 };
static void
recalc_timings(hercules_t *dev)
{
double disptime;
double _dispontime;
double _dispofftime;
disptime = dev->crtc[0] + 1;
_dispontime = dev->crtc[1];
_dispofftime = disptime - _dispontime;
_dispontime *= HERCCONST;
_dispofftime *= HERCCONST;
dev->dispontime = (uint64_t) (_dispontime);
dev->dispofftime = (uint64_t) (_dispofftime);
}
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
};
static void
hercules_out(uint16_t addr, uint8_t val, void *priv)
{
hercules_t *dev = (hercules_t *) priv;
uint8_t old;
VIDEO_MONITOR_PROLOGUE()
switch (addr) {
case 0x03b0:
case 0x03b2:
case 0x03b4:
case 0x03b6:
dev->crtcreg = val & 31;
break;
case 0x03b1:
case 0x03b3:
case 0x03b5:
case 0x03b7:
old = dev->crtc[dev->crtcreg];
dev->crtc[dev->crtcreg] = val & crtcmask[dev->crtcreg];
/*
* Fix for Generic Turbo XT BIOS, which
* sets up cursor registers wrong.
*/
if (dev->crtc[10] == 6 && dev->crtc[11] == 7) {
dev->crtc[10] = 0xb;
dev->crtc[11] = 0xc;
}
if (old != val) {
if ((dev->crtcreg < 0xe) || (dev->crtcreg > 0x10)) {
dev->fullchange = changeframecount;
recalc_timings(dev);
}
}
break;
case 0x03b8:
old = dev->ctrl;
/* Prevent setting of bits if they are disabled in CTRL2. */
if ((old & 0x02) && !(val & 0x02))
dev->ctrl &= 0xfd;
else if ((val & 0x02) && (dev->ctrl2 & 0x01))
dev->ctrl |= 0x02;
if ((old & 0x80) && !(val & 0x80))
dev->ctrl &= 0x7f;
else if ((val & 0x80) && (dev->ctrl2 & 0x02))
dev->ctrl |= 0x80;
dev->ctrl = (dev->ctrl & 0x82) | (val & 0x7d);
if (old ^ val)
recalc_timings(dev);
break;
case 0x03b9:
case 0x03bb:
dev->lp_ff = !(addr & 0x0002);
break;
case 0x03bf:
old = dev->ctrl2;
dev->ctrl2 = val;
/* According to the Programmer's guide to the Hercules graphics cars
by David B. Doty from 1988, the CTRL2 modes (bits 1,0) are as follow:
- 00: DIAG: Text mode only, only page 0 accessible;
- 01: HALF: Graphics mode allowed, only page 0 accessible;
- 11: FULL: Graphics mode allowed, both pages accessible. */
if (val & 0x01)
mem_mapping_set_exec(&dev->mapping, dev->vram);
else
mem_mapping_set_exec(&dev->mapping, NULL);
if (val & 0x02)
mem_mapping_set_addr(&dev->mapping, 0xb0000, 0x10000);
else
mem_mapping_set_addr(&dev->mapping, 0xb0000, 0x08000);
if (old ^ val)
recalc_timings(dev);
break;
default:
break;
}
VIDEO_MONITOR_EPILOGUE()
}
static uint8_t
hercules_in(uint16_t addr, void *priv)
{
const hercules_t *dev = (hercules_t *) priv;
uint8_t ret = 0xff;
switch (addr) {
case 0x03b0:
case 0x03b2:
case 0x03b4:
case 0x03b6:
ret = dev->crtcreg;
break;
case 0x03b1:
case 0x03b3:
case 0x03b5:
case 0x03b7:
if (dev->crtcreg == 0x0c)
ret = (dev->ma >> 8) & 0x3f;
else if (dev->crtcreg == 0x0d)
ret = dev->ma & 0xff;
else
ret = dev->crtc[dev->crtcreg];
break;
case 0x03ba:
ret = 0x70; /* Hercules ident */
ret |= (dev->lp_ff ? 2 : 0);
ret |= (dev->stat & 0x01);
if (dev->stat & 0x08)
ret |= 0x80;
if ((ret & 0x81) == 0x80)
ret |= 0x08;
break;
default:
break;
}
return ret;
}
static void
hercules_waitstates(UNUSED(void *priv))
{
int ws_array[16] = { 3, 4, 5, 6, 7, 8, 4, 5, 6, 7, 8, 4, 5, 6, 7, 8 };
int ws;
ws = ws_array[cycles & 0xf];
cycles -= ws;
}
static void
hercules_write(uint32_t addr, uint8_t val, void *priv)
{
hercules_t *dev = (hercules_t *) priv;
if (dev->ctrl2 & 0x01)
addr &= 0xffff;
else
addr &= 0x0fff;
dev->vram[addr] = val;
hercules_waitstates(dev);
}
static uint8_t
hercules_read(uint32_t addr, void *priv)
{
hercules_t *dev = (hercules_t *) priv;
uint8_t ret = 0xff;
if (dev->ctrl2 & 0x01)
addr &= 0xffff;
else
addr &= 0x0fff;
hercules_waitstates(dev);
ret = dev->vram[addr];
return ret;
}
static void
hercules_render_overscan_left(hercules_t *dev)
{
uint32_t width;
if (dev->ctrl & 0x02)
width = (((uint32_t) dev->crtc[1]) << 4);
else
width = (((uint32_t) dev->crtc[1]) * 9);
if ((dev->displine + 14) < 0)
return;
if (width == 0)
return;
for (uint8_t i = 0; i < 8; i++)
buffer32->line[dev->displine + 14][i] = 0x00000000;
}
static void
hercules_render_overscan_right(hercules_t *dev)
{
uint32_t width;
if (dev->ctrl & 0x02)
width = (((uint32_t) dev->crtc[1]) << 4);
else
width = (((uint32_t) dev->crtc[1]) * 9);
if ((dev->displine + 14) < 0)
return;
if (width == 0)
return;
for (uint8_t i = 0; i < 8; i++)
buffer32->line[dev->displine + 14][8 + width + i] = 0x00000000;
}
static void
hercules_poll(void *priv)
{
hercules_t *dev = (hercules_t *) priv;
uint8_t chr;
uint8_t attr;
uint16_t ca;
uint16_t dat;
uint16_t pa;
int oldsc;
int blink;
int x;
int xx;
int y;
int yy;
int c;
int oldvc;
int drawcursor;
uint32_t *p;
VIDEO_MONITOR_PROLOGUE()
ca = (dev->crtc[15] | (dev->crtc[14] << 8)) & 0x3fff;
if (!dev->linepos) {
timer_advance_u64(&dev->timer, dev->dispofftime);
dev->stat |= 1;
dev->linepos = 1;
oldsc = dev->sc;
if ((dev->crtc[8] & 3) == 3)
dev->sc = (dev->sc << 1) & 7;
if (dev->dispon) {
if (dev->displine < dev->firstline) {
dev->firstline = dev->displine;
video_wait_for_buffer();
}
dev->lastline = dev->displine;
hercules_render_overscan_left(dev);
if (dev->ctrl & 0x02) {
ca = (dev->sc & 3) * 0x2000;
if (dev->ctrl & 0x80)
ca += 0x8000;
for (x = 0; x < dev->crtc[1]; x++) {
if (dev->ctrl & 8)
dat = (dev->vram[((dev->ma << 1) & 0x1fff) + ca] << 8) | dev->vram[((dev->ma << 1) & 0x1fff) + ca + 1];
else
dat = 0;
dev->ma++;
for (c = 0; c < 16; c++)
buffer32->line[dev->displine + 14][(x << 4) + c + 8] = (dat & (32768 >> c)) ? 7 : 0;
for (c = 0; c < 16; c += 8)
video_blend((x << 4) + c + 8, dev->displine + 14);
}
} else {
for (x = 0; x < dev->crtc[1]; x++) {
if (dev->ctrl & 8) {
/* Undocumented behavior: page 1 in text mode means characters are read
from page 1 and attributes from page 0. */
chr = dev->charbuffer[x << 1];
attr = dev->charbuffer[(x << 1) + 1];
} else
chr = attr = 0;
drawcursor = ((dev->ma == ca) && dev->con && dev->cursoron);
blink = ((dev->blink & 16) && (dev->ctrl & 0x20) && (attr & 0x80) && !drawcursor);
if (dev->sc == 12 && ((attr & 7) == 1)) {
for (c = 0; c < 9; c++)
buffer32->line[dev->displine + 14][(x * 9) + c + 8] = dev->cols[attr][blink][1];
} else {
for (c = 0; c < 8; c++)
buffer32->line[dev->displine + 14][(x * 9) + c + 8] = dev->cols[attr][blink][(fontdatm[chr][dev->sc] & (1 << (c ^ 7))) ? 1 : 0];
if ((chr & ~0x1f) == 0xc0)
buffer32->line[dev->displine + 14][(x * 9) + 8 + 8] = dev->cols[attr][blink][fontdatm[chr][dev->sc] & 1];
else
buffer32->line[dev->displine + 14][(x * 9) + 8 + 8] = dev->cols[attr][blink][0];
}
if (dev->ctrl2 & 0x01)
dev->ma = (dev->ma + 1) & 0x3fff;
else
dev->ma = (dev->ma + 1) & 0x7ff;
if (drawcursor) {
for (c = 0; c < 9; c++)
buffer32->line[dev->displine + 14][(x * 9) + c + 8] ^= dev->cols[attr][0][1];
}
}
}
hercules_render_overscan_right(dev);
if (dev->ctrl & 0x02)
x = dev->crtc[1] << 4;
else
x = dev->crtc[1] * 9;
video_process_8(x + 16, dev->displine + 14);
}
dev->sc = oldsc;
if (dev->vc == dev->crtc[7] && !dev->sc)
dev->stat |= 8;
dev->displine++;
if (dev->displine >= 500)
dev->displine = 0;
} else {
timer_advance_u64(&dev->timer, dev->dispontime);
if (dev->dispon)
dev->stat &= ~1;
dev->linepos = 0;
if (dev->vsynctime) {
dev->vsynctime--;
if (!dev->vsynctime)
dev->stat &= ~8;
}
if (dev->sc == (dev->crtc[11] & 31) || ((dev->crtc[8] & 3) == 3 && dev->sc == ((dev->crtc[11] & 31) >> 1))) {
dev->con = 0;
dev->coff = 1;
}
if (dev->vadj) {
dev->sc++;
dev->sc &= 31;
dev->ma = dev->maback;
dev->vadj--;
if (!dev->vadj) {
dev->dispon = 1;
dev->ma = dev->maback = (dev->crtc[13] | (dev->crtc[12] << 8)) & 0x3fff;
dev->sc = 0;
}
} else if (((dev->crtc[8] & 3) != 3 && dev->sc == dev->crtc[9]) || ((dev->crtc[8] & 3) == 3 && dev->sc == (dev->crtc[9] >> 1))) {
dev->maback = dev->ma;
dev->sc = 0;
oldvc = dev->vc;
dev->vc++;
dev->vc &= 127;
if (dev->vc == dev->crtc[6])
dev->dispon = 0;
if (oldvc == dev->crtc[4]) {
dev->vc = 0;
dev->vadj = dev->crtc[5];
if (!dev->vadj) {
dev->dispon = 1;
dev->ma = dev->maback = (dev->crtc[13] | (dev->crtc[12] << 8)) & 0x3fff;
}
switch (dev->crtc[10] & 0x60) {
case 0x20:
dev->cursoron = 0;
break;
case 0x60:
dev->cursoron = dev->blink & 0x10;
break;
default:
dev->cursoron = dev->blink & 0x08;
break;
}
}
if (dev->vc == dev->crtc[7]) {
dev->dispon = 0;
dev->displine = 0;
if ((dev->crtc[8] & 3) == 3)
dev->vsynctime = ((int32_t) dev->crtc[4] * ((dev->crtc[9] >> 1) + 1)) + dev->crtc[5] - dev->crtc[7] + 1;
else
dev->vsynctime = ((int32_t) dev->crtc[4] * (dev->crtc[9] + 1)) + dev->crtc[5] - dev->crtc[7] + 1;
if (dev->crtc[7]) {
if (dev->ctrl & 0x02)
x = dev->crtc[1] << 4;
else
x = dev->crtc[1] * 9;
dev->lastline++;
y = (dev->lastline - dev->firstline);
if ((dev->ctrl & 8) && x && y && ((x != xsize) || (y != ysize) || video_force_resize_get())) {
xsize = x;
ysize = y;
if (xsize < 64)
xsize = enable_overscan ? 640 : 656;
if (ysize < 32)
ysize = 200;
set_screen_size(xsize + (enable_overscan ? 16 : 0), ysize + (enable_overscan ? 28 : 0));
if (video_force_resize_get())
video_force_resize_set(0);
}
if ((x >= 160) && ((y + 1) >= 120)) {
/* Draw (overscan_size) lines of overscan on top and bottom. */
for (yy = 0; yy < 14; yy++) {
p = &(buffer32->line[(dev->firstline + yy) & 0x7ff][0]);
for (xx = 0; xx < (x + 16); xx++)
p[xx] = 0x00000000;
}
for (yy = 0; yy < 14; yy++) {
p = &(buffer32->line[(dev->firstline + 14 + y + yy) & 0x7ff][0]);
for (xx = 0; xx < (x + 16); xx++)
p[xx] = 0x00000000;
}
}
if (enable_overscan)
video_blit_memtoscreen(0, dev->firstline, xsize + 16, ysize + 28);
else
video_blit_memtoscreen(8, dev->firstline + 14, xsize, ysize);
frames++;
#if 0
if ((dev->ctrl & 2) && (dev->ctrl2 & 1)) {
#endif
if (dev->ctrl & 0x02) {
video_res_x = dev->crtc[1] * 16;
video_res_y = dev->crtc[6] * 4;
video_bpp = 1;
} else {
video_res_x = dev->crtc[1];
video_res_y = dev->crtc[6];
video_bpp = 0;
}
}
dev->firstline = 1000;
dev->lastline = 0;
dev->blink++;
}
} else {
dev->sc++;
dev->sc &= 31;
dev->ma = dev->maback;
}
if (dev->sc == (dev->crtc[10] & 31) || ((dev->crtc[8] & 3) == 3 && dev->sc == ((dev->crtc[10] & 31) >> 1)))
dev->con = 1;
if (dev->dispon && !(dev->ctrl & 0x02)) {
for (x = 0; x < (dev->crtc[1] << 1); x++) {
pa = (dev->ctrl & 0x80) ? ((x & 1) ? 0x0000 : 0x8000) : 0x0000;
dev->charbuffer[x] = dev->vram[(((dev->ma << 1) + x) & 0x3fff) + pa];
}
}
}
VIDEO_MONITOR_EPILOGUE()
}
static void *
hercules_init(UNUSED(const device_t *info))
{
hercules_t *dev;
dev = (hercules_t *) malloc(sizeof(hercules_t));
memset(dev, 0x00, sizeof(hercules_t));
dev->monitor_index = monitor_index_global;
overscan_x = 16;
overscan_y = 28;
dev->vram = (uint8_t *) malloc(0x10000);
timer_add(&dev->timer, hercules_poll, dev, 1);
mem_mapping_add(&dev->mapping, 0xb0000, 0x08000,
hercules_read, NULL, NULL, hercules_write, NULL, NULL,
NULL /*dev->vram*/, MEM_MAPPING_EXTERNAL, dev);
io_sethandler(0x03b0, 16,
hercules_in, NULL, NULL, hercules_out, NULL, NULL, dev);
for (uint16_t c = 0; c < 256; c++) {
dev->cols[c][0][0] = dev->cols[c][1][0] = dev->cols[c][1][1] = 16;
if (c & 0x08)
dev->cols[c][0][1] = 15 + 16;
else
dev->cols[c][0][1] = 7 + 16;
}
dev->cols[0x70][0][1] = 16;
dev->cols[0x70][0][0] = dev->cols[0x70][1][0] = dev->cols[0x70][1][1] = 16 + 15;
dev->cols[0xF0][0][1] = 16;
dev->cols[0xF0][0][0] = dev->cols[0xF0][1][0] = dev->cols[0xF0][1][1] = 16 + 15;
dev->cols[0x78][0][1] = 16 + 7;
dev->cols[0x78][0][0] = dev->cols[0x78][1][0] = dev->cols[0x78][1][1] = 16 + 15;
dev->cols[0xF8][0][1] = 16 + 7;
dev->cols[0xF8][0][0] = dev->cols[0xF8][1][0] = dev->cols[0xF8][1][1] = 16 + 15;
dev->cols[0x00][0][1] = dev->cols[0x00][1][1] = 16;
dev->cols[0x08][0][1] = dev->cols[0x08][1][1] = 16;
dev->cols[0x80][0][1] = dev->cols[0x80][1][1] = 16;
dev->cols[0x88][0][1] = dev->cols[0x88][1][1] = 16;
overscan_x = overscan_y = 0;
cga_palette = device_get_config_int("rgb_type") << 1;
if (cga_palette > 6)
cga_palette = 0;
cgapal_rebuild();
herc_blend = device_get_config_int("blend");
video_inform(VIDEO_FLAG_TYPE_MDA, &timing_hercules);
/* Force the LPT3 port to be enabled. */
lpt3_init(0x3BC);
return dev;
}
static void
hercules_close(void *priv)
{
hercules_t *dev = (hercules_t *) priv;
if (!dev)
return;
if (dev->vram)
free(dev->vram);
free(dev);
}
static void
speed_changed(void *priv)
{
hercules_t *dev = (hercules_t *) priv;
recalc_timings(dev);
}
static const device_config_t hercules_config[] = {
// clang-format off
{
.name = "rgb_type",
.description = "Display type",
.type = CONFIG_SELECTION,
.default_int = 0,
.selection = {
{
.description = "Default",
.value = 0
},
{
.description = "Green",
.value = 1
},
{
.description = "Amber",
.value = 2
},
{
.description = "Gray",
.value = 3
},
{
.description = ""
}
}
},
{
.name = "blend",
.description = "Blend",
.type = CONFIG_BINARY,
.default_int = 1
},
{
.type = CONFIG_END
}
// clang-format on
};
const device_t hercules_device = {
.name = "Hercules",
.internal_name = "hercules",
.flags = DEVICE_ISA,
.local = 0,
.init = hercules_init,
.close = hercules_close,
.reset = NULL,
{ .available = NULL },
.speed_changed = speed_changed,
.force_redraw = NULL,
.config = hercules_config
};