> I've just reworked it again to avoid reading the status from
> the interrupt controller.  Test program gives 2.85us

Unfortunately today's experiments seem to indicate that you
don't get sensible byte values by reading the unlatched
8254 registers.  It looks as though you can read a byte that
is in the process of being decremented :-(

I think it is possible to avoid the ICU read though.
(by enabling interrupts! and seeing if one happened....)

	David

-- 
David Laight: david@l8s.co.uk