Re: Interrupt jitter on Kuper Control RTMC48 Motion Control Card?

["Paul Crawford (at UoD)" <psc@sat.dundee.ac.uk>]

We make use of dosemu for antenna control and use the IRQ-5 interrupt 
line along with the timer-0 interrupts for our own software.

Our main reason for keeping with DOS is simplicity - we don't need to 
change the working software or worry about device driver updates. 
However, we were keen to move from Windows 95 to LINUX/dosemu due to the 
great improvement in security (from none to good!) and networking.

We find the IRQ-5 hardware interrupt seems to get through pretty 
reliably, but the timer-0 stuff can go AWOL for over 0.25 seconds at 
times. We run dosemu with nice level -11 (to prioritise over the 
X-server) and disable any cron jobs that could take away host time 
significantly at regular intervals.

I don't know about the particular card you use, but the cases where we 
used stepper motors the hardware controlled the stepping, and only the 
reaching of set points or detecting of limit/reference positions relied 
on rapid response from the software.

Maybe not much help, but just to share our experience.

Regards,
Paul
-- 
Dr. Paul S. Crawford
Satellite Station
Dundee University
Small's Wynd, Dundee,
DD1 4HN, U.K.
Tel: +44 (0)1382 38 4687
The University of Dundee is a Scottish Registered Charity, No. SC015096