>could the interrupt routine do nothing but make a beep
>sound?
You have to program the pc-speaker directly.
I uploaded some Docomentation on how to do this to
http://www.stud.uni-goettingen.de/~jappel/pub/pcspeaker.zip for
To make it actually beep is more complicated than to make it simply click
if an Interrupt is recieved.To do the latter you have to the following:
Port 0x61 controls how the speaker will operate as follows:
Bit 0 Effect
0 The state of the speaker will follow bit 1 of port 61h
1 The speaker will be connected to PIT channel 2, bit 1 is
used as switch ie 0 = not connected, 1 = connected.
First clear the lower two bits of port 0x61:
outb(inb(0x61) & !3, 0x61);
In your Interrupt-Routine you might then toggle bit 1 of Port 0x61.
Every toggling gives a click to the speaker. If the toggle-frequency f is
high enough you will hear a tone of frequency f/2.
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