Accepting inputs VIA PC

[mixinguiness@xxxxxxxxx]

I am new to HA and I tried searching but here is what I would like to
do:

I have a lot of parts from access and security systems. I would like to
create or use some software and hardware that will allow me to monitor
these NO or NC circuts VIA my PC.

I have a controller built that will create outputs VIA the parallel
port... but I would like to have inputs as well. Is there any prefab
hardware and software that will allow me to do this?

Thaks for the info.

Vinny