401 lines
12 KiB
C
401 lines
12 KiB
C
/*
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* 86Box A hypervisor and IBM PC system emulator that specializes in
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* running old operating systems and software designed for IBM
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* PC systems and compatibles from 1981 through fairly recent
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* system designs based on the PCI bus.
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*
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* This file is part of the 86Box distribution.
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*
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* MDA emulation.
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*
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*
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*
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* Authors: Sarah Walker, <https://pcem-emulator.co.uk/>
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* Miran Grca, <mgrca8@gmail.com>
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*
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* Copyright 2008-2019 Sarah Walker.
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* Copyright 2016-2019 Miran Grca.
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*/
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#include <stdio.h>
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#include <stdint.h>
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#include <string.h>
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#include <stdlib.h>
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#include <wchar.h>
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#include <86box/86box.h>
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#include <86box/io.h>
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#include <86box/timer.h>
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#include <86box/lpt.h>
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#include <86box/pit.h>
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#include <86box/mem.h>
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#include <86box/rom.h>
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#include <86box/device.h>
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#include <86box/video.h>
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#include <86box/vid_mda.h>
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#include <86box/plat_unused.h>
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static int mdacols[256][2][2];
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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 };
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void mda_recalctimings(mda_t *mda);
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void
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mda_out(uint16_t addr, uint8_t val, void *priv)
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{
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mda_t *mda = (mda_t *) priv;
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switch (addr) {
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case 0x3b0:
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case 0x3b2:
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case 0x3b4:
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case 0x3b6:
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mda->crtcreg = val & 31;
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return;
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case 0x3b1:
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case 0x3b3:
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case 0x3b5:
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case 0x3b7:
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mda->crtc[mda->crtcreg] = val;
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if (mda->crtc[10] == 6 && mda->crtc[11] == 7) /*Fix for Generic Turbo XT BIOS, which sets up cursor registers wrong*/
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{
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mda->crtc[10] = 0xb;
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mda->crtc[11] = 0xc;
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}
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mda_recalctimings(mda);
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return;
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case 0x3b8:
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mda->ctrl = val;
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return;
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default:
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break;
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}
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}
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uint8_t
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mda_in(uint16_t addr, void *priv)
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{
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const mda_t *mda = (mda_t *) priv;
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switch (addr) {
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case 0x3b0:
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case 0x3b2:
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case 0x3b4:
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case 0x3b6:
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return mda->crtcreg;
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case 0x3b1:
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case 0x3b3:
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case 0x3b5:
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case 0x3b7:
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return mda->crtc[mda->crtcreg];
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case 0x3ba:
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return mda->stat | 0xF0;
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default:
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break;
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}
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return 0xff;
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}
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void
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mda_write(uint32_t addr, uint8_t val, void *priv)
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{
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mda_t *mda = (mda_t *) priv;
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mda->vram[addr & 0xfff] = val;
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}
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uint8_t
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mda_read(uint32_t addr, void *priv)
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{
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const mda_t *mda = (mda_t *) priv;
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return mda->vram[addr & 0xfff];
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}
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void
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mda_recalctimings(mda_t *mda)
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{
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double _dispontime;
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double _dispofftime;
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double disptime;
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disptime = mda->crtc[0] + 1;
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_dispontime = mda->crtc[1];
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_dispofftime = disptime - _dispontime;
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_dispontime *= MDACONST;
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_dispofftime *= MDACONST;
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mda->dispontime = (uint64_t) (_dispontime);
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mda->dispofftime = (uint64_t) (_dispofftime);
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}
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void
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mda_poll(void *priv)
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{
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mda_t *mda = (mda_t *) priv;
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uint16_t ca = (mda->crtc[15] | (mda->crtc[14] << 8)) & 0x3fff;
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int drawcursor;
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int x;
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int c;
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int oldvc;
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uint8_t chr;
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uint8_t attr;
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int oldsc;
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int blink;
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VIDEO_MONITOR_PROLOGUE()
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if (!mda->linepos) {
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timer_advance_u64(&mda->timer, mda->dispofftime);
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mda->stat |= 1;
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mda->linepos = 1;
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oldsc = mda->sc;
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if ((mda->crtc[8] & 3) == 3)
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mda->sc = (mda->sc << 1) & 7;
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if (mda->dispon) {
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if (mda->displine < mda->firstline) {
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mda->firstline = mda->displine;
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video_wait_for_buffer();
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}
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mda->lastline = mda->displine;
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for (x = 0; x < mda->crtc[1]; x++) {
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chr = mda->vram[(mda->ma << 1) & 0xfff];
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attr = mda->vram[((mda->ma << 1) + 1) & 0xfff];
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drawcursor = ((mda->ma == ca) && mda->con && mda->cursoron);
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blink = ((mda->blink & 16) && (mda->ctrl & 0x20) && (attr & 0x80) && !drawcursor);
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if (mda->sc == 12 && ((attr & 7) == 1)) {
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for (c = 0; c < 9; c++)
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buffer32->line[mda->displine][(x * 9) + c] = mdacols[attr][blink][1];
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} else {
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for (c = 0; c < 8; c++)
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buffer32->line[mda->displine][(x * 9) + c] = mdacols[attr][blink][(fontdatm[chr + mda->fontbase][mda->sc] & (1 << (c ^ 7))) ? 1 : 0];
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if ((chr & ~0x1f) == 0xc0)
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buffer32->line[mda->displine][(x * 9) + 8] = mdacols[attr][blink][fontdatm[chr + mda->fontbase][mda->sc] & 1];
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else
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buffer32->line[mda->displine][(x * 9) + 8] = mdacols[attr][blink][0];
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}
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mda->ma++;
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if (drawcursor) {
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for (c = 0; c < 9; c++)
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buffer32->line[mda->displine][(x * 9) + c] ^= mdacols[attr][0][1];
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}
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}
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video_process_8(mda->crtc[1] * 9, mda->displine);
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}
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mda->sc = oldsc;
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if (mda->vc == mda->crtc[7] && !mda->sc) {
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mda->stat |= 8;
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}
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mda->displine++;
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if (mda->displine >= 500)
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mda->displine = 0;
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} else {
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timer_advance_u64(&mda->timer, mda->dispontime);
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if (mda->dispon)
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mda->stat &= ~1;
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mda->linepos = 0;
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if (mda->vsynctime) {
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mda->vsynctime--;
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if (!mda->vsynctime) {
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mda->stat &= ~8;
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}
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}
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if (mda->sc == (mda->crtc[11] & 31) || ((mda->crtc[8] & 3) == 3 && mda->sc == ((mda->crtc[11] & 31) >> 1))) {
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mda->con = 0;
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mda->coff = 1;
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}
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if (mda->vadj) {
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mda->sc++;
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mda->sc &= 31;
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mda->ma = mda->maback;
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mda->vadj--;
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if (!mda->vadj) {
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mda->dispon = 1;
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mda->ma = mda->maback = (mda->crtc[13] | (mda->crtc[12] << 8)) & 0x3fff;
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mda->sc = 0;
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}
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} else if (mda->sc == mda->crtc[9] || ((mda->crtc[8] & 3) == 3 && mda->sc == (mda->crtc[9] >> 1))) {
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mda->maback = mda->ma;
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mda->sc = 0;
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oldvc = mda->vc;
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mda->vc++;
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mda->vc &= 127;
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if (mda->vc == mda->crtc[6])
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mda->dispon = 0;
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if (oldvc == mda->crtc[4]) {
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mda->vc = 0;
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mda->vadj = mda->crtc[5];
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if (!mda->vadj)
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mda->dispon = 1;
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if (!mda->vadj)
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mda->ma = mda->maback = (mda->crtc[13] | (mda->crtc[12] << 8)) & 0x3fff;
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if ((mda->crtc[10] & 0x60) == 0x20)
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mda->cursoron = 0;
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else
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mda->cursoron = mda->blink & 16;
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}
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if (mda->vc == mda->crtc[7]) {
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mda->dispon = 0;
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mda->displine = 0;
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mda->vsynctime = 16;
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if (mda->crtc[7]) {
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x = mda->crtc[1] * 9;
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mda->lastline++;
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if ((x != xsize) || ((mda->lastline - mda->firstline) != ysize) || video_force_resize_get()) {
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xsize = x;
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ysize = mda->lastline - mda->firstline;
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if (xsize < 64)
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xsize = 656;
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if (ysize < 32)
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ysize = 200;
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set_screen_size(xsize, ysize);
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if (video_force_resize_get())
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video_force_resize_set(0);
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}
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video_blit_memtoscreen(0, mda->firstline, xsize, ysize);
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frames++;
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video_res_x = mda->crtc[1];
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video_res_y = mda->crtc[6];
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video_bpp = 0;
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}
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mda->firstline = 1000;
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mda->lastline = 0;
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mda->blink++;
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}
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} else {
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mda->sc++;
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mda->sc &= 31;
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mda->ma = mda->maback;
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}
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if (mda->sc == (mda->crtc[10] & 31) || ((mda->crtc[8] & 3) == 3 && mda->sc == ((mda->crtc[10] & 31) >> 1))) {
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mda->con = 1;
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}
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}
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VIDEO_MONITOR_EPILOGUE();
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}
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void
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mda_init(mda_t *mda)
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{
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for (uint16_t c = 0; c < 256; c++) {
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mdacols[c][0][0] = mdacols[c][1][0] = mdacols[c][1][1] = 16;
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if (c & 8)
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mdacols[c][0][1] = 15 + 16;
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else
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mdacols[c][0][1] = 7 + 16;
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}
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mdacols[0x70][0][1] = 16;
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mdacols[0x70][0][0] = mdacols[0x70][1][0] = mdacols[0x70][1][1] = 16 + 15;
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mdacols[0xF0][0][1] = 16;
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mdacols[0xF0][0][0] = mdacols[0xF0][1][0] = mdacols[0xF0][1][1] = 16 + 15;
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mdacols[0x78][0][1] = 16 + 7;
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mdacols[0x78][0][0] = mdacols[0x78][1][0] = mdacols[0x78][1][1] = 16 + 15;
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mdacols[0xF8][0][1] = 16 + 7;
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mdacols[0xF8][0][0] = mdacols[0xF8][1][0] = mdacols[0xF8][1][1] = 16 + 15;
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mdacols[0x00][0][1] = mdacols[0x00][1][1] = 16;
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mdacols[0x08][0][1] = mdacols[0x08][1][1] = 16;
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mdacols[0x80][0][1] = mdacols[0x80][1][1] = 16;
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mdacols[0x88][0][1] = mdacols[0x88][1][1] = 16;
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overscan_x = overscan_y = 0;
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mda->monitor_index = monitor_index_global;
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cga_palette = device_get_config_int("rgb_type") << 1;
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if (cga_palette > 6) {
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cga_palette = 0;
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}
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cgapal_rebuild();
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timer_add(&mda->timer, mda_poll, mda, 1);
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}
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void *
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mda_standalone_init(UNUSED(const device_t *info))
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{
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mda_t *mda = malloc(sizeof(mda_t));
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memset(mda, 0, sizeof(mda_t));
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video_inform(VIDEO_FLAG_TYPE_MDA, &timing_mda);
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mda->vram = malloc(0x1000);
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mem_mapping_add(&mda->mapping, 0xb0000, 0x08000, mda_read, NULL, NULL, mda_write, NULL, NULL, NULL, MEM_MAPPING_EXTERNAL, mda);
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io_sethandler(0x03b0, 0x0010, mda_in, NULL, NULL, mda_out, NULL, NULL, mda);
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mda_init(mda);
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lpt3_init(0x3BC);
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return mda;
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}
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void
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mda_setcol(int chr, int blink, int fg, uint8_t cga_ink)
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{
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mdacols[chr][blink][fg] = 16 + cga_ink;
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}
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void
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mda_close(void *priv)
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{
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mda_t *mda = (mda_t *) priv;
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free(mda->vram);
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free(mda);
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}
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void
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mda_speed_changed(void *priv)
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{
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mda_t *mda = (mda_t *) priv;
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mda_recalctimings(mda);
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}
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static const device_config_t mda_config[] = {
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// clang-format off
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{
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.name = "rgb_type",
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.description = "Display type",
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.type = CONFIG_SELECTION,
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.default_int = 0,
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.selection = {
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{
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.description = "Default",
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.value = 0
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},
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{
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.description = "Green",
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.value = 1
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},
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{
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.description = "Amber",
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.value = 2
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},
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{
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.description = "Gray",
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.value = 3
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},
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{
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.description = ""
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}
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}
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},
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{
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.type = CONFIG_END
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}
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// clang-format on
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};
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const device_t mda_device = {
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.name = "IBM MDA",
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.internal_name = "mda",
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.flags = DEVICE_ISA,
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.local = 0,
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.init = mda_standalone_init,
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.close = mda_close,
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.reset = NULL,
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{ .available = NULL },
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.speed_changed = mda_speed_changed,
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.force_redraw = NULL,
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.config = mda_config
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};
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