Minimal Monitor http://en.wikipedia.org/wiki/Machine_code_monitor http://www.reddit.com/r/programming/comments/9x15g/programming_thought_experiment_stuck_in_a_room/c0ewj2c

gistfile1.txt

typedef void (*function)();
char program[32];
int main() {
  char *t = program;
  unsigned i, n;
  for (;;) {
    for (i = 3; i; i--) {
      n = getch() - '0';
      if (n > 7) (*(function)program)();
      *t = *t * 8 + n;
    }
    t++;
  }
}