Path: utzoo!utgpu!news-server.csri.toronto.edu!rpi!zaphod.mps.ohio-state.edu!mips!apple!agate!ucbvax!dog.ee.lbl.gov!ucsd!sdcc6!jclark
From: jclark@sdcc6.ucsd.edu (John Clark)
Newsgroups: comp.sys.atari.st
Subject: Re: TEAC SCSI floppy summary
Message-ID: <18774@sdcc6.ucsd.edu>
Date: 28 Apr 91 21:11:33 GMT
References: <12649@uhccux.uhcc.Hawaii.Edu>
Organization: University of California, San Diego
Lines: 21

In article <12649@uhccux.uhcc.Hawaii.Edu> kiki@uhunix1.uhcc.Hawaii.Edu (Jack W. Wine) writes:
+driver and formatter programs.  Another concerns the procedure TOS performs
+at bootup.  Will TOS interrogate the SCSI floppy and obtain its parameters?

The TEAC SCSI Floppies I've worked on do not 'sense' the format of
the disk in the drive. They require a 'MODE SELECT' SCSI command to
configure them to the 'desired' density. If you wish to support
multiple densities or a density which is not the 'default'(I think
it's IBM 720K) then the TOS startup will have send the different
configuration to the drive. I don't think TOS naturally does this.

Also on the drive, at least of Rev G or lower, is a 300 ms powerup
wait time where the drive does not respond to "UNIT READY" commands
and so if your init routines buzzes the device before the 300 ms is up
you get the impression that the drive is not there. Many 'Hard'
disks at least repond to 'REQUEST SENSE' and 'UNIT READY' with a
'I'm busy' response. The TEAC appears dead.
-- 

John Clark
jclark@ucsd.edu