[comp.lang.pascal] Interrupts and high-resolution timing under Windows

oivindt@bio.uio.no (Oivind Toien) (05/06/91)

I need a high resolution timer function (at least 100Hz) that works
under win 3.0 to trigger an A/D conversion routine.

The resolution of the timer function in windows is usually to low (55
ms) to be used for timing an A/D conversion routine. In addition, the
priority of timer messages are quite low, so that samples could be
lost because of mouse events. It seems that the only way to go is to
use an interrupt routine (although the only thing I found in the
Petzold book about this is that you should stay with the timer
function :-( ).

I have two interrupt routines that runs fine under DOS (Turbo-pascal).
They both use the Setintvect function to attach Int $1C (the user
timer interrupt) to an interrupt routine. 

When running the same routine under TPW the debugger shows that the
address is set correctly to the interrupt routine. But the routine does
not seem to be activated. Has anyone has got this to work in either C
or TPW? (If interest i can mail the source that works under dos).

If someone have some example code they would be willing to share
it would be highly appreciated too.
--
Oivind Toien   <oivindt@ulrik.uio.no>
Div. of General Physiology, Dept. of Biology, Univ. of Oslo
P.O. Box 1051, N-0316 Oslo 3, NORWAY  
Phone+47-2-454732  Fax+47-2-454726