Jim wrote:

snip

The general problem is going to be that WINXP, 2000, Vista, and NT make
it difficult to use the printer port pins directly. Not impossible, but
certainly a problem.


Please see http://www.beyondlogic.org/porttalk/porttalk.htm for the 'allowio
driver' for interrupt-based parallel port access. The 'JWA' logic analyzer
software 'digitrace' uses this on NT-based Windows with good results.
The logic analyzer software is at:
http://www.xs4all.nl/%7Ejwasys/old/ select 'DigiTrace' in the left frame.

Regards,

Michael