Ref: 09580004
Title: Purpose of "Vendor ID" Option of TAPETEST
Date: 1/4/91

Copyright 3Com Corporation, 1991.  All rights reserved.

All tape drives, controllers, and (embedded) disk drives differ in
various ways, at least in their sense byte structure and in the format of
their "mode select" commands.

The purpose of the "Vendor ID" option (option A) of TAPETEST is to
tell the backup software (3+Backup or 3+Open Backup) what type of tape drive
is being used.  When the software knows what type the drive is, it can send
the proper set-up information to the drive using the "mode select" command,
and the software will know how to interpret all sense byte responses from the
drive.

What happens if the "Vendor Type" was not set?

With a single drive type available, the backup software does not need to know
what kind of tape drive is being used, because it will be built into the
software.  With multiple drive vendors, if the drive type is not specified,
the software will not send proper command(s), and the drive will reject the
command(s).

