[PD-dev] fast hardware access / timimg on Win

Olaf Matthes olaf.matthes at gmx.de
Sat Dec 21 00:46:19 CET 2002

Hi developers,

I'd like to access the parallel port from an external. The problem is
the speed: I need more than 1000 (in words: one thousand) accesses per
I've tried using the IRQ and a callback function but Windows seems to
have limitations that result in a maximum callback interval of 1
millisecond. That's still to slow for my purposes.
Another idea was to put the hardware acces into the dsp routine and read
out the bytes from the parport every - say - 16 samples. But this won't
give a periodic access because the execution time of the dsp loop
depends on processing time and as long as my external doesn't do any
other audio stuff it executes much to fast.

Does anybody know how to get access to the IRQs on Win faster than every
millisecond? Or is there a way to send a child thread to sleep for a
period shorter than 1 millisecond (it appears to me that 1 millisecond
is the shortest time interval Win can handle).... ?

thanks a lot,

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