The sane-umax library implements a SANE backend that provides acces to several UMAX-SCSI-scanners. Parallel- and USB- scanners are not supported!
If you own a UMAX-SCSI-scanner that is not listed as supported, it may work with SANE. It depends on the information the scanner returns to the umax-backend. If the data-block is large enough, the backend prints a warning and continues, but it is possible that not everything works fine.I suggest you hold one hand on the power-button of the scanner while you try the first scans!