This is a very simple driver for Blue Chip Technology's PCI Data Acquisition Card (PCIADC):
http://www.bluechiptechnology.co.uk/Product/PCIADC-Data-Aquisition-Card
It was used successfully to read analog inputs, but has not been used (or updated) in some years.
I'm putting this here mainly as an archive, but if anyone finds it useful, by all means use it.
MIT Licensed