2ca4ead570
Misc ViRGE fixes. Changes to memory mapping. Changes to PCI handling. Disabled 'AMI WinBIOS 486 PCI' due to incomplete chipset emulation. Invalid GUS register reads no longer kill the emulator.
323 lines
12 KiB
C
323 lines
12 KiB
C
/*MDA emulation*/
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#include <stdlib.h>
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#include "ibm.h"
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#include "device.h"
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#include "io.h"
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#include "mem.h"
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#include "timer.h"
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#include "video.h"
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#include "vid_mda.h"
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typedef struct mda_t
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{
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mem_mapping_t mapping;
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uint8_t crtc[32];
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int crtcreg;
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uint8_t ctrl, stat;
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int dispontime, dispofftime;
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int vidtime;
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int firstline, lastline;
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int linepos, displine;
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int vc, sc;
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uint16_t ma, maback;
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int con, coff, cursoron;
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int dispon, blink;
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int vsynctime, vadj;
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uint8_t *vram;
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} mda_t;
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static int mdacols[256][2][2];
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void mda_recalctimings(mda_t *mda);
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void mda_out(uint16_t addr, uint8_t val, void *p)
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{
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mda_t *mda = (mda_t *)p;
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switch (addr)
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{
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case 0x3b0: case 0x3b2: case 0x3b4: case 0x3b6:
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mda->crtcreg = val & 31;
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return;
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case 0x3b1: case 0x3b3: case 0x3b5: 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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}
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}
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uint8_t mda_in(uint16_t addr, void *p)
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{
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mda_t *mda = (mda_t *)p;
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switch (addr)
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{
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case 0x3b0: case 0x3b2: case 0x3b4: case 0x3b6:
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return mda->crtcreg;
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case 0x3b1: case 0x3b3: case 0x3b5: 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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}
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return 0xff;
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}
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void mda_write(uint32_t addr, uint8_t val, void *p)
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{
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mda_t *mda = (mda_t *)p;
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egawrites++;
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mda->vram[addr & 0xfff] = val;
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}
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uint8_t mda_read(uint32_t addr, void *p)
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{
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mda_t *mda = (mda_t *)p;
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egareads++;
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return mda->vram[addr & 0xfff];
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}
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void mda_recalctimings(mda_t *mda)
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{
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double _dispontime, _dispofftime, 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 = (int)(_dispontime * (1 << TIMER_SHIFT));
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mda->dispofftime = (int)(_dispofftime * (1 << TIMER_SHIFT));
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}
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void mda_poll(void *p)
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{
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mda_t *mda = (mda_t *)p;
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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, c;
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int oldvc;
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uint8_t chr, attr;
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int cols[4];
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int oldsc;
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int blink;
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if (!mda->linepos)
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{
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mda->vidtime += 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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{
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if (mda->displine < mda->firstline)
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{
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mda->firstline = mda->displine;
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}
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mda->lastline = mda->displine;
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cols[0] = 0;
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cols[1] = 7;
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for (x = 0; x < mda->crtc[1]; x++)
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{
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chr = mda->vram[(mda->ma << 1) & 0x3fff];
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attr = mda->vram[((mda->ma << 1) + 1) & 0x3fff];
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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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{
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for (c = 0; c < 9; c++)
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buffer->line[mda->displine][(x * 9) + c] = mdacols[attr][blink][1];
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}
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else
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{
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for (c = 0; c < 8; c++)
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buffer->line[mda->displine][(x * 9) + c] = mdacols[attr][blink][(fontdatm[chr][mda->sc] & (1 << (c ^ 7))) ? 1 : 0];
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if ((chr & ~0x1f) == 0xc0) buffer->line[mda->displine][(x * 9) + 8] = mdacols[attr][blink][fontdatm[chr][mda->sc] & 1];
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else buffer->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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{
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for (c = 0; c < 9; c++)
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buffer->line[mda->displine][(x * 9) + c] ^= mdacols[attr][0][1];
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}
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}
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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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{
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mda->stat |= 8;
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// printf("VSYNC on %i %i\n",vc,sc);
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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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}
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else
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{
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mda->vidtime += mda->dispontime;
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if (mda->dispon) mda->stat&=~1;
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mda->linepos=0;
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if (mda->vsynctime)
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{
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mda->vsynctime--;
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if (!mda->vsynctime)
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{
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mda->stat&=~8;
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// printf("VSYNC off %i %i\n",vc,sc);
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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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{
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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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{
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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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{
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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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}
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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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{
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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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{
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// printf("Display over at %i\n",displine);
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mda->vc = 0;
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mda->vadj = mda->crtc[5];
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if (!mda->vadj) mda->dispon = 1;
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if (!mda->vadj) mda->ma = mda->maback = (mda->crtc[13] | (mda->crtc[12] << 8)) & 0x3fff;
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if ((mda->crtc[10] & 0x60) == 0x20) mda->cursoron = 0;
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else mda->cursoron = mda->blink & 16;
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}
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if (mda->vc == mda->crtc[7])
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{
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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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{
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// printf("Lastline %i Firstline %i %i\n",lastline,firstline,lastline-firstline);
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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)
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{
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xsize = x;
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ysize = mda->lastline - mda->firstline;
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// printf("Resize to %i,%i - R1 %i\n",xsize,ysize,crtcm[1]);
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if (xsize < 64) xsize = 656;
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if (ysize < 32) ysize = 200;
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updatewindowsize(xsize, ysize);
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}
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startblit();
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video_blit_memtoscreen_8(0, mda->firstline, xsize, mda->lastline - mda->firstline);
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endblit();
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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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}
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else
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{
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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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{
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mda->con = 1;
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// printf("Cursor on - %02X %02X %02X\n",crtcm[8],crtcm[10],crtcm[11]);
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}
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}
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}
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void *mda_init()
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{
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int c;
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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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mda->vram = malloc(0x1000);
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timer_add(mda_poll, &mda->vidtime, TIMER_ALWAYS_ENABLED, mda);
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mem_mapping_add(&mda->mapping, 0xb0000, 0x08000, mda_read, NULL, NULL, mda_write, NULL, NULL, NULL, 0, mda);
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io_sethandler(0x03b0, 0x0010, mda_in, NULL, NULL, mda_out, NULL, NULL, mda);
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for (c = 0; c < 256; c++)
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{
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mdacols[c][0][0] = mdacols[c][1][0] = mdacols[c][1][1] = 16;
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if (c & 8) mdacols[c][0][1] = 15 + 16;
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else 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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return mda;
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}
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void mda_close(void *p)
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{
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mda_t *mda = (mda_t *)p;
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free(mda->vram);
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free(mda);
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}
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void mda_speed_changed(void *p)
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{
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mda_t *mda = (mda_t *)p;
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mda_recalctimings(mda);
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}
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device_t mda_device =
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{
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"MDA",
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0,
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mda_init,
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mda_close,
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NULL,
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mda_speed_changed,
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NULL,
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NULL
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};
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