Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!csd4.milw.wisc.edu!lll-winken!uunet!zephyr!tektronix!sequent!mntgfx!dclemans
From: dclemans@mentor.com (Dave Clemans @ APD x1292)
Newsgroups: comp.sys.atari.st
Subject: Re: Question on 1.44 meg drives...
Message-ID: <1989Jun27.154710.1798@mentor.com>
Date: 27 Jun 89 15:47:10 GMT
References: <8906261817.AA17231@jade.berkeley.edu>
Organization: engr
Lines: 27

From article <8906261817.AA17231@jade.berkeley.edu>, by WSCART01@ULKYVX.BITNET:
> 
>  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?
> 

1.44 Meg drives are NOT 160 track drives; they are 80 track drives.
The difference is the bit rate to/from the drive; 1.44 Meg drives are twice
as fast, and thus can store twice as much data.

The Western Digital disk controller chip used by the ST is not able to
handle anything other than the current clock rates.

If you want to use a 1.44 Meg drive on an ST, the only known alternatives are:

    buy a "Discovery Cartridge"

    find a 1.44 Meg floppy with a SCSI interface, and treat it as a small
    hard disk

    do some MAJOR hacking on the mother board and in the OS to switch to a
    more general disk controller

dgc