Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!cs.utexas.edu!usc!polyslo!jdudeck
From: jdudeck@polyslo.CalPoly.EDU (John R. Dudeck)
Newsgroups: comp.sys.ibm.pc
Subject: Re: Formatting 3.5" Diskette
Message-ID: <25ae618c.4904@polyslo.CalPoly.EDU>
Date: 12 Jan 90 23:00:28 GMT
References: <7439@shlump.nac.dec.com>
Reply-To: jdudeck@polyslo.CalPoly.EDU (John R. Dudeck)
Organization: Cal Poly State University -- San Luis Obispo
Lines: 17


In article <7439@shlump.nac.dec.com> goldstein@carafe.enet.dec.com (Fred R. Goldstein) writes:
>[Concerning a 3.5" drive that doesn't detect the diskette type.]
>I can 
>use DD disks as HD without punching additional holes.

Actually in my earlier posting I didn't go into the gory details of how my
system responds.  In fact my Toshiba 3.5" drive knows whether I have inserted
a 720k or 1.44m diskette by looking at the hole in the diskette.  It adjusts
its recording current according to the type, and if I try to format 1.44 m
on a lo-density dikette, it fails on track 0 every time.  There is a jumper
on the drive that causes it to ignore the hole, and then I can format up
to almost the whole diskette at 1.44 m.

However, this is not the answer to the question of how to get DOS to detect
what type of diskette you have inserted, and adjust its number of sectors
and recording density accordingly.  I know that some systems can do this.

-- 
John Dudeck                           "You want to read the code closely..." 
jdudeck@Polyslo.CalPoly.Edu             -- C. Staley, in OS course, teaching 
ESL: 62013975 Tel: 805-545-9549          Tanenbaum's MINIX operating system.