From: jvahn@short.circuit.com (James Vahn)
Barry Block wrote:
> What else can I use as a timer so that the speed is the same on all
> machines?
Try OUT 4Fh, AL in a loop. My notes mention 8Dh will work too. 
Maybe someone here can explain better, but my understanding is that the
ports under FFh all use the motherboard BUS speed of 8 to 10 MHz and this
is standard on all 80X86 boards. The reason for an OUT is that the CPU
will wait (I need help here) until the OUT is finished, unlike reading a
port. Since a write is needed, it must be an unused port, and it appears
4Fh is a good candidate.
...  The Moon is Full
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