https://geekhack.org/index.php?topic=54706.msg1856618#msg1856618
static void enable_break(void)
{
print("Enable break: ");
+ while (ibm4704_send(0xFC)) { _delay_ms(10); }
// valid scancode: 00-79h
- for (uint8_t code = 0; code < 0x7A; code++) {
+ for (uint8_t code = 0; code < 0x7F; code++) {
while (ibm4704_send(0x80|code)) _delay_ms(10);
_delay_ms(5); // wait for response
// No response(FF) when ok, FD when out of bound