Unfortunately, UMAX has decided that the programming information for their parellel-port scanners is proprietary. They hold the crazed belief that they have found out secrets about the parallel port that no one knows, and that no one could reverse-engineer their drivers to figure them out. Hello, anyone home at UMAX? You had a clue, once...
Until UMAX gets a clue or someone gets around to reverse-engineering their parallel protocols, UMAX parallel port scanners will not be supported. If you don't like this, I encourage you to contact UMAX and very politely request that they make their parallel port scanner protocols available.
The driver I wrote currently can handle most single-pass and three-pass UMAX scanners. The 0.5 version is the current stable version; Oliver Rauch is currently working on adding many enhancements to the driver in the 0.5.x versions (he has more than doubled the size of the source code!) and they are the current development tree. His work will be merged back into my sources when I have time to do it.
Oliver added to the driver the capability to be a backend driver for the SANE (Scanner Access Now Easy) scanner framework. This means, among other things, that it is possible to scan from within The GIMP using a UMAX, Mustek, HP, or other scanner. You can even grab images straight from a quickcam into The GIMP.