Hi to all! I have completed a (very dirty) reverse engineered driver prototype for the Canon MP750 scanner/printer. It can be found at http://schueler.brgkepler.at/calbert/mp750/mp750.c The program uses libusb. The scanner pulls in one page from the paper shaft, scans it and sends the data to the program which writes a pnm to stdout.
One test scan at: http://schueler.brgkepler.at/calbert/mp750/test3.jpg everything seems to run quite well. (If someone tries it and the scanner gets on fire, you've been warned ;-). mine still works.) Will now try to decode the protocol in detail and start to develop a basic sane backend. If someone owns an MP750 or MP780 for further testing, please let me know. cheers, chris