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Add MDA colour support. Kind of crappy implementatio

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starfrost013
2025-06-16 20:45:11 +01:00
parent 5d8b3412e9
commit a0da500c38
2 changed files with 71 additions and 19 deletions
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2
src/include/86box/vid_mda.h
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@@ -61,7 +61,7 @@ typedef enum mda_crtc_registers_e
typedef enum mda_mode_flags_e
{
MDA_MODE_HIGHRES = 1 << 0, // MUST be enabled for sane operation
MDA_MODE_BLACKANDWHITE = 1 << 1, // UNUSED in most cases. Not present on Hercules
MDA_MODE_BW = 1 << 1, // UNUSED in most cases. Not present on Hercules
MDA_MODE_VIDEO_ENABLE = 1 << 3,
MDA_MODE_BLINK = 1 << 5,
} mda_mode_flags;

88
src/video/vid_mda.c
View File

@@ -6,7 +6,7 @@
*
* This file is part of the 86Box distribution.
*
* MDA emulation.
* IBM Monochrome Display and Printer Adapter emulation.
*
*
*
@@ -18,6 +18,7 @@
* Copyright 2016-2025 Miran Grca.
* Copyright 2025 starfrost / Connor Hyde
*/
#include <stdbool.h>
#include <stdio.h>
#include <stdint.h>
#include <string.h>
@@ -35,6 +36,17 @@
#include <86box/vid_mda.h>
#include <86box/plat_unused.h>
// Enumerates MDA monitor types
enum mda_monitor_type_e
{
MDA_MONITOR_TYPE_DEFAULT = 0, // Default MDA monitor type.
MDA_MONITOR_TYPE_GREEN = 1, // Green phosphor
MDA_MONITOR_TYPE_AMBER = 2, // Amber phosphor
MDA_MONITOR_TYPE_GRAY = 3, // Gray phosphor
MDA_MONITOR_TYPE_RGBI = 4, // RGBI colour monitor with modified rev1 or rev0 MDA card for colour support
} mda_monitor_type;
// [attr][blink][fg]
static int mda_attr_to_color_table[256][2][2];
static video_timings_t timing_mda = { .type = VIDEO_ISA, .write_b = 8, .write_w = 16, .write_l = 32, .read_b = 8, .read_w = 16, .read_l = 32 };
@@ -155,32 +167,66 @@ mda_poll(void *priv)
scanline_old = mda->scanline;
if ((mda->crtc[MDA_CRTC_INTERLACE] & 3) == 3)
mda->scanline = (mda->scanline << 1) & 7;
if (mda->dispon) {
if (mda->displine < mda->firstline) {
if (mda->dispon)
{
if (mda->displine < mda->firstline)
{
mda->firstline = mda->displine;
video_wait_for_buffer();
}
mda->lastline = mda->displine;
for (x = 0; x < mda->crtc[MDA_CRTC_HDISP]; x++) {
for (x = 0; x < mda->crtc[MDA_CRTC_HDISP]; x++)
{
chr = mda->vram[(mda->memaddr << 1) & 0xfff];
attr = mda->vram[((mda->memaddr << 1) + 1) & 0xfff];
drawcursor = ((mda->memaddr == cursoraddr) && mda->cursorvisible && mda->cursoron);
blink = ((mda->blink & 16) && (mda->mode & MDA_MODE_BLINK) && (attr & 0x80) && !drawcursor);
if (mda->scanline == 12 && ((attr & 7) == 1)) {
int32_t color_bg = 0, color_fg = 0;
// If we are using an RGBI monitor allow colour
//if (cga_palette == MDA_MONITOR_TYPE_RGBI)
//{
if (!(mda->mode & MDA_MODE_BW))
{
color_bg = (attr >> 4) & 0x0F;
color_fg = (attr & 0x0F);
}
//}
if (mda->scanline == 12 && ((attr & 7) == 1)) { // underline
for (c = 0; c < 9; c++)
buffer32->line[mda->displine][(x * 9) + c] = mda_attr_to_color_table[attr][blink][1];
buffer32->line[mda->displine][(x * 9) + c] = mda_attr_to_color_table[attr][blink][1] | color_bg;
} else {
for (c = 0; c < 8; c++)
buffer32->line[mda->displine][(x * 9) + c] = mda_attr_to_color_table[attr][blink][(fontdatm[chr + mda->fontbase][mda->scanline] & (1 << (c ^ 7))) ? 1 : 0];
{
//bg=0, fg=1
bool is_fg = (fontdatm[chr + mda->fontbase][mda->scanline] & (1 << (c ^ 7))) ? 1 : 0;
uint32_t font_char = mda_attr_to_color_table[attr][blink][is_fg];
if (!(mda->mode & MDA_MODE_BW))
{
if (!is_fg)
font_char = 16 + color_bg;
else
font_char = 16 + color_fg;
}
buffer32->line[mda->displine][(x * 9) + c] = font_char;
}
if ((chr & ~0x1f) == 0xc0)
buffer32->line[mda->displine][(x * 9) + 8] = mda_attr_to_color_table[attr][blink][fontdatm[chr + mda->fontbase][mda->scanline] & 1];
else
buffer32->line[mda->displine][(x * 9) + 8] = mda_attr_to_color_table[attr][blink][0];
buffer32->line[mda->displine][(x * 9) + 8] = mda_attr_to_color_table[attr][blink][0] | color_bg;
}
mda->memaddr++;
if (drawcursor) {
for (c = 0; c < 9; c++)
buffer32->line[mda->displine][(x * 9) + c] ^= mda_attr_to_color_table[attr][0][1];
buffer32->line[mda->displine][(x * 9) + c] ^= mda_attr_to_color_table[attr][0][1] | color_fg;
}
}
@@ -289,6 +335,7 @@ mda_poll(void *priv)
void
mda_init(mda_t *mda)
{
for (uint16_t c = 0; c < 256; c++) {
mda_attr_to_color_table[c][0][0] = mda_attr_to_color_table[c][1][0] = mda_attr_to_color_table[c][1][1] = 16;
if (c & 8)
@@ -308,6 +355,7 @@ mda_init(mda_t *mda)
mda_attr_to_color_table[0x08][0][1] = mda_attr_to_color_table[0x08][1][1] = 16;
mda_attr_to_color_table[0x80][0][1] = mda_attr_to_color_table[0x80][1][1] = 16;
mda_attr_to_color_table[0x88][0][1] = mda_attr_to_color_table[0x88][1][1] = 16;
overscan_x = overscan_y = 0;
mda->monitor_index = monitor_index_global;
@@ -387,6 +435,7 @@ mda_speed_changed(void *priv)
mda_recalctimings(mda);
}
static const device_config_t mda_config[] = {
// clang-format off
{
@@ -397,12 +446,14 @@ static const device_config_t mda_config[] = {
.default_int = 0,
.file_filter = NULL,
.spinner = { 0 },
.selection = {
{ .description = "Default", .value = 0 },
{ .description = "Green", .value = 1 },
{ .description = "Amber", .value = 2 },
{ .description = "Gray", .value = 3 },
{ .description = "" }
.selection =
{
{ .description = "Default", .value = MDA_MONITOR_TYPE_DEFAULT },
{ .description = "Green", .value = MDA_MONITOR_TYPE_GREEN },
{ .description = "Amber", .value = MDA_MONITOR_TYPE_AMBER },
{ .description = "Gray", .value = MDA_MONITOR_TYPE_GRAY },
{ .description = "Generic RGBI color monitor", .value = MDA_MONITOR_TYPE_RGBI },
{ .description = "" }
},
.bios = { { 0 } }
},
@@ -414,12 +465,13 @@ static const device_config_t mda_config[] = {
.default_int = 0,
.file_filter = NULL,
.spinner = { 0 },
.selection = {
{ .description = "US (CP 437)", .value = 0 },
.selection =
{
{ .description = "US (CP 437)", .value = 0 },
{ .description = "IBM Nordic (CP 437-Nordic)", .value = 1 },
{ .description = "Czech Kamenicky (CP 895) #1", .value = 2 },
{ .description = "Czech Kamenicky (CP 895) #2", .value = 3 },
{ .description = "" }
{ .description = "" }
},
.bios = { { 0 } }
},