JB> I am also interested in working with parallel ports. I would like to u
JB> port to trip an alarm....or several if possible.
 
JB> I am currently using 2 serial ports for data collection. Is it possibl
JB> address each of the 8 data lines of the parallel port individually and
JB> the +5 volts to activate a solid state relay of some kind.
 
Yes, you can address each data line individually.  There are also some
open collector outputs that are addressable on another register, but
don't think they could handle the current of a relay.  I have only
worked with mechanical type relays, and typically just build a
Darlington amp out of a couple npn transistors to drive the relay.  You
can also use the chips like ULN2003 for this purpose.  I don't see why
you couldn't use the same technique to drive a solid state relay.  I
use the parallel port on my bbs computer to control an AC outlet box I
made and it works great.  I also made a stepper motor controller
circuit for a class one time (before discovering the UCN5804B chip) and
controlled it with parallel port.  Its a good source of digital i/o
lines.  Do you have access to the web?  There is a good faq on parallel
ports on one site, I'll write it down and post it, or you could email
me at hbcsc388@huey.csun.edu and I'll attach it back to you.     Eric
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