Files
86Box/src/video/vid_nga.c
2025-02-08 01:28:25 -05:00

680 lines
27 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.
*
* Emulation of the NCR NGA (K511, K201) video cards.
*
*
*
* Authors: Sarah Walker, <https://pcem-emulator.co.uk/>
* Miran Grca, <mgrca8@gmail.com>
* Fred N. van Kempen, <decwiz@yahoo.com>
* EngiNerd, <webmaster.crrc@yahoo.it>
*
* Copyright 2008-2019 Sarah Walker.
* Copyright 2016-2019 Miran Grca.
* Copyright 2017-2019 Fred N. van Kempen.
* Copyright 2020 EngiNerd.
*/
#include <stdio.h>
#include <stdint.h>
#include <string.h>
#include <stdlib.h>
#include <stdarg.h>
#include <wchar.h>
#include <86box/io.h>
#include <86box/video.h>
#include <86box/86box.h>
#include <86box/timer.h>
#include <86box/mem.h>
#include <86box/pit.h>
#include <86box/rom.h>
#include <86box/device.h>
#include <86box/vid_cga.h>
#include <86box/vid_nga.h>
#include <86box/vid_cga_comp.h>
#include <86box/plat_unused.h>
#define CGA_RGB 0
#define CGA_COMPOSITE 1
#define COMPOSITE_OLD 0
#define COMPOSITE_NEW 1
static video_timings_t timing_nga = { .type = VIDEO_ISA, .write_b = 8, .write_w = 16, .write_l = 32, .read_b = 8, .read_w = 16, .read_l = 32 };
void
nga_recalctimings(nga_t *nga)
{
double _dispontime;
double _dispofftime;
double disptime;
if (nga->cga.cgamode & 1) {
disptime = nga->cga.crtc[0] + 1;
_dispontime = nga->cga.crtc[1];
} else {
disptime = (nga->cga.crtc[0] + 1) << 1;
_dispontime = nga->cga.crtc[1] << 1;
}
_dispofftime = disptime - _dispontime;
_dispontime *= CGACONST / 2;
_dispofftime *= CGACONST / 2;
nga->cga.dispontime = (uint64_t) (_dispontime);
nga->cga.dispofftime = (uint64_t) (_dispofftime);
}
void
nga_out(uint16_t addr, uint8_t val, void *priv)
{
nga_t *nga = (nga_t *) priv;
cga_out(addr, val, &nga->cga);
}
uint8_t
nga_in(uint16_t addr, void *priv)
{
nga_t *nga = (nga_t *) priv;
return cga_in(addr, &nga->cga);
}
void
nga_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];
sub_cycles(ws);
}
void
nga_write(uint32_t addr, uint8_t val, void *priv)
{
nga_t *nga = (nga_t *) priv;
int offset;
/* a8000-affff */
if (!(addr & 0x10000))
nga->vram_64k[addr & 0x7FFF] = val;
/* b8000-bffff */
else
nga->cga.vram[addr & 0x7FFF] = val;
if (nga->cga.snow_enabled) {
/* recreate snow effect */
offset = ((timer_get_remaining_u64(&nga->cga.timer) / CGACONST) * 4) & 0xfc;
nga->cga.charbuffer[offset] = nga->cga.vram[addr & 0x7fff];
nga->cga.charbuffer[offset | 1] = nga->cga.vram[addr & 0x7fff];
}
nga_waitstates(&nga->cga);
}
uint8_t
nga_read(uint32_t addr, void *priv)
{
nga_t *nga = (nga_t *) priv;
int offset;
uint8_t ret;
/* a8000-affff */
if (!(addr & 0x10000))
ret = nga->vram_64k[addr & 0x7FFF];
else
ret = nga->cga.vram[addr & 0x7FFF];
nga_waitstates(&nga->cga);
if (nga->cga.snow_enabled) {
/* recreate snow effect */
offset = ((timer_get_remaining_u64(&nga->cga.timer) / CGACONST) * 4) & 0xfc;
nga->cga.charbuffer[offset] = nga->cga.vram[addr & 0x7fff];
nga->cga.charbuffer[offset | 1] = nga->cga.vram[addr & 0x7fff];
}
return ret;
}
void
nga_poll(void *priv)
{
nga_t *nga = (nga_t *) priv;
/* set cursor position in memory */
uint16_t ca = (nga->cga.crtc[15] | (nga->cga.crtc[14] << 8)) & 0x3fff;
int drawcursor;
int x;
int c;
int xs_temp;
int ys_temp;
int oldvc;
uint8_t chr;
uint8_t attr;
uint16_t dat;
uint16_t dat2;
int cols[4];
int col;
int oldsc;
/* graphic mode and not high-res modes */
if ((nga->cga.cgamode & 2) && !(nga->cga.cgamode & 0x40)) {
/* standard cga mode */
cga_poll(&nga->cga);
return;
} else {
/* high-res or text mode */
if (!nga->cga.linepos) {
timer_advance_u64(&nga->cga.timer, nga->cga.dispofftime);
nga->cga.cgastat |= 1;
nga->cga.linepos = 1;
oldsc = nga->cga.sc;
/* if interlaced */
if ((nga->cga.crtc[8] & 3) == 3)
nga->cga.sc = ((nga->cga.sc << 1) + nga->cga.oddeven) & 7;
if (nga->cga.cgadispon) {
if (nga->cga.displine < nga->cga.firstline) {
nga->cga.firstline = nga->cga.displine;
video_wait_for_buffer();
}
nga->cga.lastline = nga->cga.displine;
/* 80-col */
if ((nga->cga.cgamode & 1) && !(nga->cga.cgamode & 2)) {
/* for each text column */
for (x = 0; x < nga->cga.crtc[1]; x++) {
/* video output enabled */
if (nga->cga.cgamode & 8) {
/* character */
chr = nga->cga.charbuffer[x << 1];
/* text attributes */
attr = nga->cga.charbuffer[(x << 1) + 1];
} else
chr = attr = 0;
/* check if cursor has to be drawn */
drawcursor = ((nga->cga.ma == ca) && nga->cga.con && nga->cga.cursoron);
/* set foreground */
cols[1] = (attr & 15) + 16;
/* blink active */
if (nga->cga.cgamode & 0x20) {
cols[0] = ((attr >> 4) & 7) + 16;
/* attribute 7 active and not cursor */
if ((nga->cga.cgablink & 8) && (attr & 0x80) && !nga->cga.drawcursor) {
/* set blinking */
cols[1] = cols[0];
}
} else {
/* Set intensity bit */
cols[0] = (attr >> 4) + 16;
}
if (drawcursor) {
for (c = 0; c < 8; c++)
buffer32->line[nga->cga.displine][(x << 3) + c + 8] = cols[(fontdatm[chr][((nga->cga.sc & 7) << 1) | nga->lineff] & (1 << (c ^ 7))) ? 1 : 0] ^ 15;
} else {
for (c = 0; c < 8; c++)
buffer32->line[nga->cga.displine][(x << 3) + c + 8] = cols[(fontdatm[chr][((nga->cga.sc & 7) << 1) | nga->lineff] & (1 << (c ^ 7))) ? 1 : 0];
}
nga->cga.ma++;
}
}
/* 40-col */
else if (!(nga->cga.cgamode & 2)) {
/* for each text column */
for (x = 0; x < nga->cga.crtc[1]; x++) {
if (nga->cga.cgamode & 8) {
chr = nga->cga.vram[((nga->cga.ma << 1) & 0x3fff) + nga->base];
attr = nga->cga.vram[(((nga->cga.ma << 1) + 1) & 0x3fff) + nga->base];
} else {
chr = attr = 0;
}
drawcursor = ((nga->cga.ma == ca) && nga->cga.con && nga->cga.cursoron);
/* set foreground */
cols[1] = (attr & 15) + 16;
/* blink active */
if (nga->cga.cgamode & 0x20) {
cols[0] = ((attr >> 4) & 7) + 16;
if ((nga->cga.cgablink & 8) && (attr & 0x80) && !nga->cga.drawcursor) {
/* set blinking */
cols[1] = cols[0];
}
} else {
/* Set intensity bit */
cols[0] = (attr >> 4) + 16;
}
if (drawcursor) {
for (c = 0; c < 8; c++)
buffer32->line[nga->cga.displine][(x << 4) + (c << 1) + 8] = buffer32->line[nga->cga.displine][(x << 4) + (c << 1) + 1 + 8] = cols[(fontdatm[chr][((nga->cga.sc & 7) << 1) | nga->lineff] & (1 << (c ^ 7))) ? 1 : 0] ^ 15;
} else {
for (c = 0; c < 8; c++)
buffer32->line[nga->cga.displine][(x << 4) + (c << 1) + 8] = buffer32->line[nga->cga.displine][(x << 4) + (c << 1) + 1 + 8] = cols[(fontdatm[chr][((nga->cga.sc & 7) << 1) | nga->lineff] & (1 << (c ^ 7))) ? 1 : 0];
}
nga->cga.ma++;
}
} else {
/* high res modes */
if (nga->cga.cgamode & 0x40) {
/* 640x400x2 mode */
if (nga->cga.cgamode & 0x4 || nga->cga.cgamode & 0x10) {
/*
* Scanlines are read in the following order:
* 0b8000-0b9f3f even scans (0,4,...)
* 0ba000-0bbf3f odd scans (2,6,...)
* 0bc000-0bdf3f even scans (1,5,...)
* 0be000-0bff3f odd scans (3,7,...)
*/
dat2 = ((nga->cga.sc & 1) * 0x2000) | (nga->lineff * 0x4000);
cols[0] = 0;
cols[1] = 15 + 16;
/* 640x400x4 mode */
} else {
cols[0] = (nga->cga.cgacol & 15) | 16;
col = (nga->cga.cgacol & 16) ? 24 : 16;
if (nga->cga.cgamode & 4) {
cols[1] = col | 3; /* Cyan */
cols[2] = col | 4; /* Red */
cols[3] = col | 7; /* White */
} else if (nga->cga.cgacol & 32) {
cols[1] = col | 3; /* Cyan */
cols[2] = col | 5; /* Magenta */
cols[3] = col | 7; /* White */
} else {
cols[1] = col | 2; /* Green */
cols[2] = col | 4; /* Red */
cols[3] = col | 6; /* Yellow */
}
/*
* Scanlines are read in the following order:
* 0b8000-0bbf3f even scans (0,4,...)
* 0bc000-0bff3f odd scans (1,5,...)
* 0a8000-0abf3f even scans (2,6,...)
* 0ac000-0aff3f odd scans (3,7,...)
*/
dat2 = (nga->cga.sc & 1) * 0x4000;
}
} else {
dat2 = (nga->cga.sc & 1) * 0x2000;
cols[0] = 0;
cols[1] = (nga->cga.cgacol & 15) + 16;
}
/* for each text column */
for (x = 0; x < nga->cga.crtc[1]; x++) {
/* video out */
if (nga->cga.cgamode & 8) {
/* 640x400x2 */
if (nga->cga.cgamode & 0x4 || nga->cga.cgamode & 0x10) {
/* read two bytes at a time */
dat = (nga->cga.vram[((nga->cga.ma << 1) & 0x1fff) + dat2] << 8) | nga->cga.vram[((nga->cga.ma << 1) & 0x1fff) + dat2 + 1];
/* each pixel is represented by one bit, so draw 16 pixels at a time */
/* crtc[1] is 40 column, so 40x16=640 pixels */
for (c = 0; c < 16; c++) {
buffer32->line[nga->cga.displine][(x << 4) + c + 8] = cols[dat >> 15];
dat <<= 1;
}
/* 640x400x4 */
} else {
/* lines 2,3,6,7,etc. */
if (nga->cga.sc & 2)
/* read two bytes at a time */
dat = (nga->vram_64k[((nga->cga.ma << 1) & 0x7fff) + dat2] << 8) | nga->vram_64k[((nga->cga.ma << 1) & 0x7fff) + dat2 + 1];
/* lines 0,1,4,5,etc. */
else
/* read two bytes at a time */
dat = (nga->cga.vram[((nga->cga.ma << 1) & 0x7fff) + dat2] << 8) | nga->cga.vram[((nga->cga.ma << 1) & 0x7fff) + dat2 + 1];
/* each pixel is represented by two bits, so draw 8 pixels at a time */
/* crtc[1] is 80 column, so 80x8=640 pixels */
for (c = 0; c < 8; c++) {
buffer32->line[nga->cga.displine][(x << 3) + c + 8] = cols[dat >> 14];
dat <<= 2;
}
}
} else {
dat = 0;
}
nga->cga.ma++;
}
}
} else {
/* nga specific */
cols[0] = ((nga->cga.cgamode & 0x12) == 0x12) ? 0 : (nga->cga.cgacol & 15) + 16;
/* 80-col */
if (nga->cga.cgamode & 1) {
hline(buffer32, 0, (nga->cga.displine << 1), ((nga->cga.crtc[1] << 3) + 16) << 2, cols[0]);
hline(buffer32, 0, (nga->cga.displine << 1) + 1, ((nga->cga.crtc[1] << 3) + 16) << 2, cols[0]);
} else {
hline(buffer32, 0, (nga->cga.displine << 1), ((nga->cga.crtc[1] << 4) + 16) << 2, cols[0]);
hline(buffer32, 0, (nga->cga.displine << 1) + 1, ((nga->cga.crtc[1] << 4) + 16) << 2, cols[0]);
}
}
if (nga->cga.cgamode & 1)
/* set screen width */
x = (nga->cga.crtc[1] << 3) + 16;
else
x = (nga->cga.crtc[1] << 4) + 16;
video_process_8(x, nga->cga.displine);
nga->cga.sc = oldsc;
/* vertical sync */
if (nga->cga.vc == nga->cga.crtc[7] && !nga->cga.sc)
nga->cga.cgastat |= 8;
nga->cga.displine++;
if (nga->cga.displine >= 720)
nga->cga.displine = 0;
} else {
timer_advance_u64(&nga->cga.timer, nga->cga.dispontime);
if (nga->cga.cgadispon)
nga->cga.cgastat &= ~1;
nga->cga.linepos = 0;
/* nga specific */
nga->lineff ^= 1;
/* text mode or 640x400x2 */
if (nga->lineff && !((nga->cga.cgamode & 1) && (nga->cga.cgamode & 0x40))) {
nga->cga.ma = nga->cga.maback;
/* 640x400x4 */
} else {
if (nga->cga.vsynctime) {
nga->cga.vsynctime--;
if (!nga->cga.vsynctime)
nga->cga.cgastat &= ~8;
}
/* cursor stop scanline */
if (nga->cga.sc == (nga->cga.crtc[11] & 31) || ((nga->cga.crtc[8] & 3) == 3 && nga->cga.sc == ((nga->cga.crtc[11] & 31) >> 1))) {
nga->cga.con = 0;
nga->cga.coff = 1;
}
/* interlaced and max scanline per char reached */
if ((nga->cga.crtc[8] & 3) == 3 && nga->cga.sc == (nga->cga.crtc[9] >> 1))
nga->cga.maback = nga->cga.ma;
if (nga->cga.vadj) {
nga->cga.sc++;
nga->cga.sc &= 31;
nga->cga.ma = nga->cga.maback;
nga->cga.vadj--;
if (!nga->cga.vadj) {
nga->cga.cgadispon = 1;
/* change start of displayed page (crtc 12-13) */
nga->cga.ma = nga->cga.maback = (nga->cga.crtc[13] | (nga->cga.crtc[12] << 8)) & 0x7fff;
nga->cga.sc = 0;
}
/* nga specific */
/* end of character line reached */
} else if (nga->cga.sc == nga->cga.crtc[9] || ((nga->cga.crtc[8] & 3) == 3 && nga->cga.sc == (nga->cga.crtc[9] >> 1))) {
nga->cga.maback = nga->cga.ma;
nga->cga.sc = 0;
oldvc = nga->cga.vc;
nga->cga.vc++;
nga->cga.vc &= 127;
/* lines of character displayed */
if (nga->cga.vc == nga->cga.crtc[6])
nga->cga.cgadispon = 0;
/* total vertical lines */
if (oldvc == nga->cga.crtc[4]) {
nga->cga.vc = 0;
/* adjust vertical lines */
nga->cga.vadj = nga->cga.crtc[5];
if (!nga->cga.vadj) {
nga->cga.cgadispon = 1;
/* change start of displayed page (crtc 12-13) */
nga->cga.ma = nga->cga.maback = (nga->cga.crtc[13] | (nga->cga.crtc[12] << 8)) & 0x7fff;
}
/* cursor start */
switch (nga->cga.crtc[10] & 0x60) {
case 0x20:
nga->cga.cursoron = 0;
break;
case 0x60:
nga->cga.cursoron = nga->cga.cgablink & 0x10;
break;
default:
nga->cga.cursoron = nga->cga.cgablink & 0x08;
break;
}
}
/* vertical line position */
if (nga->cga.vc == nga->cga.crtc[7]) {
nga->cga.cgadispon = 0;
nga->cga.displine = 0;
/* nga specific */
nga->cga.vsynctime = 16;
/* vsync pos */
if (nga->cga.crtc[7]) {
if (nga->cga.cgamode & 1)
/* set screen width */
x = (nga->cga.crtc[1] << 3) + 16;
else
x = (nga->cga.crtc[1] << 4) + 16;
nga->cga.lastline++;
xs_temp = x;
ys_temp = (nga->cga.lastline - nga->cga.firstline);
if ((xs_temp > 0) && (ys_temp > 0)) {
if (xsize < 64)
xs_temp = 656;
/* nga specific */
if (ysize < 32)
ys_temp = 400;
if (!enable_overscan)
xs_temp -= 16;
if ((nga->cga.cgamode & 8) && ((xs_temp != xsize) || (ys_temp != ysize) || video_force_resize_get())) {
xsize = xs_temp;
ysize = ys_temp;
set_screen_size(xsize, ysize + (enable_overscan ? 16 : 0));
if (video_force_resize_get())
video_force_resize_set(0);
}
/* nga specific */
if (enable_overscan) {
video_blit_memtoscreen(0, (nga->cga.firstline - 8),
xsize, (nga->cga.lastline - nga->cga.firstline) + 16);
} else {
video_blit_memtoscreen(8, nga->cga.firstline,
xsize, (nga->cga.lastline - nga->cga.firstline));
}
}
frames++;
video_res_x = xsize;
video_res_y = ysize;
/* 80-col */
if ((nga->cga.cgamode & 1) && !(nga->cga.cgamode & 0x40)) {
video_res_x /= 8;
video_res_y /= (nga->cga.crtc[9] + 1) * 2;
video_bpp = 0;
/* 40-col */
} else if (!(nga->cga.cgamode & 2)) {
video_res_x /= 16;
video_res_y /= (nga->cga.crtc[9] + 1) * 2;
video_bpp = 0;
} else if (nga->cga.cgamode & 0x40) {
video_res_x /= 8;
video_res_y /= 2;
video_bpp = 1;
}
}
nga->cga.firstline = 1000;
nga->cga.lastline = 0;
nga->cga.cgablink++;
nga->cga.oddeven ^= 1;
}
} else {
nga->cga.sc++;
nga->cga.sc &= 31;
nga->cga.ma = nga->cga.maback;
}
if (nga->cga.cgadispon)
nga->cga.cgastat &= ~1;
/* enable cursor if its scanline was reached */
if (nga->cga.sc == (nga->cga.crtc[10] & 31) || ((nga->cga.crtc[8] & 3) == 3 && nga->cga.sc == ((nga->cga.crtc[10] & 31) >> 1)))
nga->cga.con = 1;
}
/* 80-columns */
if (nga->cga.cgadispon && (nga->cga.cgamode & 1)) {
/* for each character per line */
for (x = 0; x < (nga->cga.crtc[1] << 1); x++)
nga->cga.charbuffer[x] = nga->cga.vram[(((nga->cga.ma << 1) + x) & 0x3fff) + nga->base];
}
}
}
}
void
nga_close(void *priv)
{
nga_t *nga = (nga_t *) priv;
free(nga->vram_64k);
free(nga->cga.vram);
free(nga);
}
void
nga_speed_changed(void *priv)
{
nga_t *nga = (nga_t *) priv;
nga_recalctimings(nga);
}
void *
nga_init(UNUSED(const device_t *info))
{
int mem;
uint8_t charset;
nga_t *nga = (nga_t *) malloc(sizeof(nga_t));
memset(nga, 0x00, sizeof(nga_t));
video_inform(VIDEO_FLAG_TYPE_CGA, &timing_nga);
charset = device_get_config_int("charset");
loadfont_ex("roms/video/nga/ncr_nga_35122.bin", 1, 4096 * charset);
nga->cga.composite = 0;
nga->cga.snow_enabled = device_get_config_int("snow_enabled");
nga->cga.vram = malloc(0x8000);
nga->vram_64k = malloc(0x8000);
timer_add(&nga->cga.timer, nga_poll, nga, 1);
mem_mapping_add(&nga->cga.mapping, 0xb8000, 0x8000,
nga_read, NULL, NULL,
nga_write, NULL, NULL, NULL, 0, nga);
mem = device_get_config_int("memory");
if (mem > 32) {
/* make optional 32KB addessable */
mem_mapping_add(&nga->mapping_64k, 0xa8000, 0x8000,
nga_read, NULL, NULL,
nga_write, NULL, NULL, NULL, 0, nga);
}
io_sethandler(0x03d0, 16, nga_in, NULL, NULL, nga_out, NULL, NULL, nga);
overscan_x = overscan_y = 16;
nga->cga.rgb_type = device_get_config_int("rgb_type");
cga_palette = (nga->cga.rgb_type << 1);
cgapal_rebuild();
return nga;
}
const device_config_t nga_config[] = {
// clang-format off
{
.name = "rgb_type",
.description = "RGB type",
.type = CONFIG_SELECTION,
.default_string = NULL,
.default_int = 0,
.file_filter = NULL,
.spinner = { 0 },
.selection = {
{ .description = "Color", .value = 0 },
{ .description = "Green Monochrome", .value = 1 },
{ .description = "Amber Monochrome", .value = 2 },
{ .description = "Gray Monochrome", .value = 3 },
{ .description = "Color (no brown)", .value = 4 },
{ .description = "" }
},
.bios = { { 0 } }
},
{
.name = "snow_enabled",
.description = "Snow emulation",
.type = CONFIG_BINARY,
.default_string = NULL,
.default_int = 1,
.file_filter = NULL,
.spinner = { 0 },
.selection = { { 0 } },
.bios = { { 0 } }
},
{
.name = "memory",
.description = "Memory size",
.type = CONFIG_SELECTION,
.default_string = NULL,
.default_int = 64,
.file_filter = NULL,
.spinner = { 0 },
.selection = {
{ .description = "32 KB", .value = 32 },
{ .description = "64 KB", .value = 64 },
{ .description = "" }
},
.bios = { { 0 } }
},
{
.name = "charset",
.description = "Character set",
.type = CONFIG_SELECTION,
.default_string = NULL,
.default_int = 0,
.file_filter = NULL,
.spinner = { 0 },
.selection = {
{ .description = "U.S. English", .value = 0 },
{ .description = "Scandinavian", .value = 1 },
{ .description = "Other languages", .value = 2 },
{ .description = "E.F. Hutton", .value = 3 },
{ .description = "" }
},
.bios = { { 0 } }
},
{ .name = "", .description = "", .type = CONFIG_END }
// clang-format on
};
const device_t nga_device = {
.name = "NCR NGA",
.internal_name = "nga",
.flags = DEVICE_ISA,
.local = 0,
.init = nga_init,
.close = nga_close,
.reset = NULL,
.available = NULL,
.speed_changed = nga_speed_changed,
.force_redraw = NULL,
.config = nga_config
};