mirror of
https://github.com/RaySollium99/picodrive.git
synced 2025-09-04 14:57:45 -04:00
cff531af94
- PicoDrive was originally released by fDave with simple
"free for non-commercial use / For commercial use, separate licencing
terms must be obtained" license and I kept it in my releases.
- in 2011, fDave re-released his code (same that I used as base
many years ago) dual licensed with GPLv2 and MAME licenses:
https://code.google.com/p/cyclone68000/
Based on the above I now proclaim that the whole source code is licensed
under the MAME license as more elaborate form of "for non-commercial use".
If that raises any doubt, I announce that all my modifications (which
is the vast majority of code by now) is licensed under the MAME license,
as it reads in COPYING file in this commit.
This does not affect ym2612.c/sn76496.c that were MAME licensed already
from the beginning.
262 lines
6.1 KiB
C
262 lines
6.1 KiB
C
/*
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* common code for pico.c and cd/pico.c
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* (C) notaz, 2007-2009
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*
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* This work is licensed under the terms of MAME license.
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* See COPYING file in the top-level directory.
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*/
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#define CYCLES_M68K_LINE 488 // suitable for both PAL/NTSC
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#define CYCLES_M68K_VINT_LAG 68
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#define CYCLES_M68K_ASD 148
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#define CYCLES_S68K_LINE 795
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#define CYCLES_S68K_VINT_LAG 111
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#define CYCLES_S68K_ASD 241
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// pad delay (for 6 button pads)
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#define PAD_DELAY \
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if (PicoOpt&POPT_6BTN_PAD) { \
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if(Pico.m.padDelay[0]++ > 25) Pico.m.padTHPhase[0]=0; \
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if(Pico.m.padDelay[1]++ > 25) Pico.m.padTHPhase[1]=0; \
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}
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// CPUS_RUN
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#ifndef CPUS_RUN
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#define CPUS_RUN(m68k_cycles,s68k_cycles) \
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SekRunM68k(m68k_cycles)
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#endif
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static int PicoFrameHints(void)
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{
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struct PicoVideo *pv=&Pico.video;
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int lines, y, lines_vis = 224, line_sample, skip, vcnt_wrap;
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int hint; // Hint counter
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pv->v_counter = Pico.m.scanline = 0;
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if ((PicoOpt&POPT_ALT_RENDERER) && !PicoSkipFrame && (pv->reg[1]&0x40)) { // fast rend., display enabled
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// draw a frame just after vblank in alternative render mode
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// yes, this will cause 1 frame lag, but this is inaccurate mode anyway.
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PicoFrameFull();
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#ifdef DRAW_FINISH_FUNC
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DRAW_FINISH_FUNC();
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#endif
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skip = 1;
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}
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else skip=PicoSkipFrame;
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if (Pico.m.pal) {
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line_sample = 68;
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if (pv->reg[1]&8) lines_vis = 240;
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} else {
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line_sample = 93;
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}
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SekCyclesReset();
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z80_resetCycles();
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#ifdef PICO_CD
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SekCyclesResetS68k();
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#endif
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PsndDacLine = 0;
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emustatus &= ~1;
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pv->status&=~0x88; // clear V-Int, come out of vblank
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hint=pv->reg[10]; // Load H-Int counter
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//dprintf("-hint: %i", hint);
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// This is to make active scan longer (needed for Double Dragon 2, mainly)
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CPUS_RUN(CYCLES_M68K_ASD, CYCLES_S68K_ASD);
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for (y = 0; y < lines_vis; y++)
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{
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pv->v_counter = Pico.m.scanline = y;
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if ((pv->reg[12]&6) == 6) { // interlace mode 2
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pv->v_counter <<= 1;
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pv->v_counter |= pv->v_counter >> 8;
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pv->v_counter &= 0xff;
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}
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// VDP FIFO
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pv->lwrite_cnt -= 12;
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if (pv->lwrite_cnt <= 0) {
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pv->lwrite_cnt=0;
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Pico.video.status|=0x200;
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}
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PAD_DELAY
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#ifdef PICO_CD
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check_cd_dma();
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#endif
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#ifdef PICO_32X
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p32x_timers_do(1);
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#endif
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// H-Interrupts:
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if (--hint < 0) // y <= lines_vis: Comix Zone, Golden Axe
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{
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hint=pv->reg[10]; // Reload H-Int counter
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pv->pending_ints|=0x10;
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if (pv->reg[0]&0x10) {
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elprintf(EL_INTS, "hint: @ %06x [%i]", SekPc, SekCycleCnt);
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SekInterrupt(4);
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}
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}
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// decide if we draw this line
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if (!skip && (PicoOpt & POPT_ALT_RENDERER))
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{
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// find the right moment for frame renderer, when display is no longer blanked
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if ((pv->reg[1]&0x40) || y > 100) {
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PicoFrameFull();
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#ifdef DRAW_FINISH_FUNC
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DRAW_FINISH_FUNC();
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#endif
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skip = 1;
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}
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}
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// get samples from sound chips
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if ((y == 224 || y == line_sample) && PsndOut)
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{
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if (Pico.m.z80Run && !Pico.m.z80_reset && (PicoOpt&POPT_EN_Z80))
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PicoSyncZ80(SekCycleCnt);
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if (ym2612.dacen && PsndDacLine <= y)
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PsndDoDAC(y);
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PsndGetSamples(y);
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}
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// Run scanline:
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if (Pico.m.dma_xfers) SekCyclesBurn(CheckDMA());
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CPUS_RUN(CYCLES_M68K_LINE, CYCLES_S68K_LINE);
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#ifdef PICO_CD
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update_chips();
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#else
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if (PicoLineHook) PicoLineHook();
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#endif
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}
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if (!skip)
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{
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if (DrawScanline < y)
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PicoDrawSync(y - 1, 0);
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#ifdef DRAW_FINISH_FUNC
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DRAW_FINISH_FUNC();
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#endif
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}
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// V-int line (224 or 240)
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Pico.m.scanline = y;
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pv->v_counter = 0xe0; // bad for 240 mode
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if ((pv->reg[12]&6) == 6) pv->v_counter = 0xc1;
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// VDP FIFO
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pv->lwrite_cnt=0;
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Pico.video.status|=0x200;
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memcpy(PicoPadInt, PicoPad, sizeof(PicoPadInt));
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PAD_DELAY
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#ifdef PICO_CD
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check_cd_dma();
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#endif
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#ifdef PICO_32X
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p32x_timers_do(1);
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#endif
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// Last H-Int:
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if (--hint < 0)
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{
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hint=pv->reg[10]; // Reload H-Int counter
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pv->pending_ints|=0x10;
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//printf("rhint: %i @ %06x [%i|%i]\n", hint, SekPc, y, SekCycleCnt);
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if (pv->reg[0]&0x10) SekInterrupt(4);
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}
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pv->status|=0x08; // go into vblank
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pv->pending_ints|=0x20;
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#ifdef PICO_32X
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p32x_start_blank();
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#endif
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// the following SekRun is there for several reasons:
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// there must be a delay after vblank bit is set and irq is asserted (Mazin Saga)
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// also delay between F bit (bit 7) is set in SR and IRQ happens (Ex-Mutants)
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// also delay between last H-int and V-int (Golden Axe 3)
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CPUS_RUN(CYCLES_M68K_VINT_LAG, CYCLES_S68K_VINT_LAG);
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if (pv->reg[1]&0x20) {
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elprintf(EL_INTS, "vint: @ %06x [%i]", SekPc, SekCycleCnt);
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SekInterrupt(6);
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}
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if (Pico.m.z80Run && !Pico.m.z80_reset && (PicoOpt&POPT_EN_Z80)) {
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PicoSyncZ80(SekCycleCnt);
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elprintf(EL_INTS, "zint");
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z80_int();
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}
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// get samples from sound chips
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if (y == 224 && PsndOut)
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{
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if (ym2612.dacen && PsndDacLine <= y)
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PsndDoDAC(y);
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PsndGetSamples(y);
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}
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// Run scanline:
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if (Pico.m.dma_xfers) SekCyclesBurn(CheckDMA());
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CPUS_RUN(CYCLES_M68K_LINE - CYCLES_M68K_VINT_LAG - CYCLES_M68K_ASD,
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CYCLES_S68K_LINE - CYCLES_S68K_VINT_LAG - CYCLES_S68K_ASD);
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#ifdef PICO_CD
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update_chips();
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#else
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if (PicoLineHook) PicoLineHook();
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#endif
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lines = scanlines_total;
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vcnt_wrap = Pico.m.pal ? 0x103 : 0xEB; // based on Gens, TODO: verify
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for (y++; y < lines; y++)
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{
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pv->v_counter = Pico.m.scanline = y;
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if (y >= vcnt_wrap)
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pv->v_counter -= Pico.m.pal ? 56 : 6;
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if ((pv->reg[12]&6) == 6)
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pv->v_counter = (pv->v_counter << 1) | 1;
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pv->v_counter &= 0xff;
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PAD_DELAY
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#ifdef PICO_CD
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check_cd_dma();
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#endif
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#ifdef PICO_32X
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p32x_timers_do(1);
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#endif
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// Run scanline:
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if (Pico.m.dma_xfers) SekCyclesBurn(CheckDMA());
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CPUS_RUN(CYCLES_M68K_LINE, CYCLES_S68K_LINE);
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#ifdef PICO_CD
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update_chips();
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#else
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if (PicoLineHook) PicoLineHook();
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#endif
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}
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// sync z80
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if (Pico.m.z80Run && !Pico.m.z80_reset && (PicoOpt&POPT_EN_Z80))
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PicoSyncZ80(Pico.m.pal ? 151809 : 127671); // cycles adjusted for converter
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if (PsndOut && ym2612.dacen && PsndDacLine <= lines-1)
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PsndDoDAC(lines-1);
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timers_cycle();
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return 0;
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}
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#undef PAD_DELAY
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#undef CPUS_RUN
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