Official PCD emulator, C (gcc)

Language: Layout:

#include <stdio.h>
#include <stdlib.h>

/*
  00 x y	MOV x, y
  01 x y	ADD x, y
  02 x y	SUB x, y
  03 x y	CMP x, y
  04 xx	JMP x
  05 x y	DAT x, y
  06 x y	BUS x, y
  070000	NOP
*/

char mem[256] = {0};
char ptr = 0;

void bus (char port, char data)
{
  switch (port)
  {
    case 0:
      exit (mem[data]);
      break;
    case 1:
      mem[data] = getchar ();
      break;
    case 2:
      putchar (mem[data]);
      break;
    case 3:
      ptr = mem[data];
      break;
    case 4:
      mem[data] = mem[ptr];
      break;
    case 5:
      mem[ptr] = mem[data];
      break;
    default: 
      mem[data] = -1;
      break;
  }
}

void run (char op[], FILE *prog)
{
  switch (op[0])
  {
    case 0: 
      mem[op[1]] = mem[op[2]];
      break;
    case 1:
      mem[op[1]] += mem[op[2]];
      break;
    case 2:
      mem[op[1]] -= mem[op[2]];
      break;
    case 3:
      if (mem[op[1]] != mem[op[2]])
        fread (op, 3, 1, prog);
      break;
    case 4:
      fseek (prog, (op[1] * 256 + op[2]) * 3, SEEK_SET);
      break;
    case 5:
      mem[op[1]] = op[2];
      break;
    case 6:
      bus (op[1], op[2]);
      break;
    case 7:
      break;
  }
}

int main (int argc, char *argv[])
{
  FILE *prog;
  char op[3];
  if (argc < 2)
  {
    puts ("argument error");
    return 1;
  }
  prog = fopen (argv[1], "rb");
  if (!prog)
  {
    puts ("file error");
    return 1;
  }
  while (!feof (prog))
  {
    if (!fread (op, 3, 1, prog))
      break;
    op[0] &= 7;
    run (op, prog);
  }
  fclose (prog);
  return 0;
}

Show compiler warnings [ + ] Compiler args [ + ] Show input
Compilation time: 0.12 sec, absolute running time: 0.15 sec, cpu time: 0.01 sec, memory peak: 5 Mb, absolute service time: 1,34 sec