Hi Phil
It worked with stdcall (WINAPI) selected!! Thank you so much.
Also, your original comment about 100% CPU use reminds my ...
I was building an industrial control system around a set of GPIB
instruments and needed a single switch input to the program. I
used the (old fashioned) joystick port switch, on the assumption that
this had hardware interrupts and would be essentially invisible to the
processor. This worked well. The program is still working
after 2 years and > 60,000 tests
The second model had a PC without a joystick, so I hacked a really
cheap USB joystick for the same function. While it worked, it
appeared that the processor was very busy and was not running my
program as it should. The joystick regularly disappeared and
required re-inserting. I gave up and used a digital line in on
the NI card that we then purchased, with no problems. I didn't
investigate at the time but maybe the USB interface was gobbling up the
processor time.
I will need to consider this with the Velleman card.
Cheers and thanks again.
John Y