ableos-idl/sysdata/programs/pcspkr/src/main.hb

stn := @use("../../../libraries/stn/src/lib.hb");
.{memory, buffer, log, string, math} := stn;
.{inb, outb} := memory

$PIT_CLOCK := 1193180

play_sound := fn(frequency: u32): void {
	div := 0

	div = PIT_CLOCK / frequency
	memory.outb(0x43, 0xB6)
	memory.outb(0x42, @intcast(div))
	memory.outb(0x42, @intcast(div >> 8))

	tmp := inb(0x61)
	if tmp != (tmp | 3) {
		outb(0x61, tmp | 3)
	}
}

no_sound := fn(): void {
	tmp := memory.inb(0x61) & 0xFC

	memory.outb(0x61, tmp)
}

beep := fn(): void {
	play_sound(1000)
	idx := 0
	loop {
		if idx >= 1000000 {
			idx += 1
		} else {
			break
		}
	}

	no_sound()
}

main := fn(): int {
	no_sound()
	beep()
	return 0
}