const __sfr __at (0x0) command;
__sfr __at (0x0) dac;
#define HALT __asm halt __endasm;
// press "2" or higher to activate...
void main() {
char i;
char j;
if (command == 0) HALT;
for (i=0; i<255; i++) {
for (j=0; j<i; j++) dac=j^i;
}
HALT;