This is the third major version of the sg driver. A summary of the sg driver history is as follows:
sg version 1 (original) from 1992 to early 1999 (lk 2.2.5) . A copy of the original HOWTO (in plain text) is at www.torque.net/sg/p/original/SCSI-Programming-HOWTO.txt
sg version 2 from lk 2.2.6 in the 2.2 series. Its documentation is available in abridged form [www.torque.net/sg/p/scsi-generic.txt] and a longer form [www.torque.net/sg/p/scsi-generic_long.txt].
sg version 3 in the linux kernel 2.4 series.
A more general description of the Linux SCSI subsystem of which sg is a part can be found in the SCSI-2.4-HOWTO.
This document was last modified on 3rd May 2002.