Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!csd4.milw.wisc.edu!bionet!ames!killer!chasm
From: chasm@killer.DALLAS.TX.US (Charles Marslett)
Newsgroups: comp.sys.atari.st
Subject: Re: Question on 1.44 meg drives...
Summary: 80 Tracks, but 500 KBPS (instead of 250 KBPS)
Message-ID: <8474@killer.DALLAS.TX.US>
Date: 28 Jun 89 03:58:21 GMT
References: <8906261817.AA17231@jade.berkeley.edu>
Organization: The Unix(R) Connection, Dallas, Texas
Lines: 29

In article <8906261817.AA17231@jade.berkeley.edu>, WSCART01@ULKYVX.BITNET writes:
> 
>  I suppose most of you are aware of 1.44 Meg drives out for the IBM. They
> use 160 tracks instead of the 80 tracks normal drives. The question i'm
> pondering is: Why has no one hooked one up to an ST? I suppose there is
> either a harware or software diffuculty to overcome. Does anyone know
> which, and exactly what the problem is?

The 1.44 MB drives, like the 1.2 MB 5 1/4" drives, still have 80 tracks of
data, but they just write more data on each track.  In particular, they
typically use an 8" drive data rate (like the 1.2 MB drives), so they get
twice as many bits per track.  (BTW, the reason the 5 1/4" drives don't get
1.44 MB per disk, like the 3 1/2" drives, is that in their case, the drive
actually spins faster when the higher data rate is in use, so they don't
write quite twice as many bits per track.

The problem with using such a drive on the Atari ST is that the controller
chip used cannot run that fast (does anyone know if a pin compatible
controller has ever been released by Western Digital or one of their com-
petitors?  That would make this possible.).

> Stuart Carter                 |      Radio astronomers can
> University Of Louisville      |      do it 24 Hours a day.

===========================================================================
Charles Marslett
STB Systems, Inc.  <== Apply all standard disclaimers
Wordmark Systems   <== No disclaimers required -- that's just me
chasm@killer.dallas.tx.us <== soon to be attctc.dallas.tx.us I think