/*
 *   emu48/src/emulate.c
 * 
 *   Copyright (C) 1995 Sebastien Carlier
 */

#include <stdio.h>
#include "emu48.h"

#define goyes(n) GOJMP = I+n; goto o_goyes;

/*               P WP*  XS   X   S   M   B   W   P  WP  XS   X   S   M   B   W*/
int F04[16] = {  4, 32,  4, 12,  4, 48,  8, 64,  4,  4,  4, 12,  4, 48,  8, 64}; 
int FRD[16] = {132,202,132,152,132,248,142,288,132,202,132,152,132,248,142,288};
int FWR[16] = {142,212,142,162,142,232,152,272,142,212,142,162,142,232,152,272};
/*               P  WP  XS   X   S   M   B   W   -   -   -   -   -   -   -   A*/
int S00[16] = {124,124,124, 68,124,124, 64,120,  0,  0,  0,  0,  0,  0,  0, 76};
/*               0   1   2   3   4   5   6   7   8   9   A   B   C   D   E   F*/
int D10[16] = {  0, 10, 20, 30, 40, 50, 60, 70, 80, 90,100,110,120,130,140,150};
int NWR[16] = {142,132,162,152,182,172,202,192,222,212,242,232,262,252,282,272};
int NRD[16] = {132,148,152,168,172,188,192,208,212,228,232,248,252,268,272,288};
/*108 874*/
char X[16];

FILE *wire;

void emulate() {
  long ticks, update_lcd, update_kbd;
  long d;
  char *I, *GOJMP, n;
  signed char jmp;

  wire = fopen("wire", "wb");
  ticks = saturn_speed;
  update_lcd=0;
  update_kbd=128;

  while (!quit) {
    if (SHUTDN) { ticks-=12; goto o_done; }
    if (pc<0x7E000) { I = rom+pc; goto o_fetch; }
    if (ISMODULE(1, pc)) { I = data[1]+pc-base[1]; goto o_fetch; }
    if (CARDSTATUS&2) if (ISMODULE(3, pc)) { I = data[3]+pc-base[3]; goto o_fetch; }
    if (CARDSTATUS&1) if (ISMODULE(4, pc)) { I = data[4]+pc-base[4]; goto o_fetch; }
    I = rom+pc;
o_fetch:

#include "fetch.h"    
#include "opcodes.h"

o_goyes:
    if (!CARRY) { pc+=2; goto o_done; }
    ticks -= 40;
    jmp = GOJMP[0] | (GOJMP[1]<<4);
    if (jmp) pc+=jmp; else pc=rstkpop();
    goto o_done;
o_invalid:
    sprintf(Buf, "Invalid Opcode at #%05lX\n", pc);
    display_warning(Buf);
    fclose(wire);
    quit = 1;
    return;
o_invalid3: pc+=3; ticks--; goto o_done;
o_invalid4: pc+=4; ticks--; goto o_done;
o_invalid5: pc+=5; ticks--; goto o_done;
o_invalid6: pc+=6; ticks--; goto o_done;
o_done:
    if (ticks>0) continue;
        /* 1/8192s has elapsed */

    ticks = saturn_speed;

    update_lcd^=1;
    if (update_lcd) { /* LCD_REFRESH 4096Hz */
      display_next();
      if (display.touched) display_redraw();
      if (ioram[0x10]&8) {
        if (ioram[0x12]&1) {
          fputc((char)Npack(ioram+0x16, 2), wire);
          ioram[0x12] = 0;
          if (ioram[0x10]&4) INTERRUPT("IO");
        }
      }
    }

    update_kbd--;
    if (update_kbd<=0) { /* KBD_UPDATE 64Hz */
      if ((ioram[0x2f]&1) == 0) update_kbd = 128;
      keyboard_update();
      if (IR15X) {
        SHUTDN = 0;
        if (!INTP) INTERRUPT("ON");
      } 
    }

    if ((ioram[0x2f]&1) == 0) continue; /* T2, T1, KBD_POLL disabled ? */

    if (t2) /* T2 8192Hz */
      t2--;
    else {
      t2 = 0xffffffff;
      if (ioram[0x2f]&4) { ioram[0x2f]|=8; SHUTDN = 0; }
      if (ioram[0x2f]&2) { ioram[0x2f]|=8; if (!INTP) INTERRUPT("T2"); }
    }

    if ((t2&0x1ff) == 0) { /* T1 16Hz */
      if (t1)
        t1--;
      else { /* 1s has elapsed */
        t1 = 0xf;
        if (ioram[0x2e]&4) { ioram[0x2e]|=8; SHUTDN = 0; }
        if (ioram[0x2e]&2) { ioram[0x2e]|=8; if (!INTP) INTERRUPT("T1"); }
      }
    }

    if (update_kbd<=0) { /* KBD_POLL 64Hz */
      update_kbd = 128;
      if (KDN_rising_edge) {
        KDN_rising_edge = 0;
        SHUTDN = 0;
        if (INTE&&(!INTP)) INTERRUPT("KP");
      }
    }

  }

  fclose(wire);
  return;
}