Path: utzoo!utdoe!generic!pnet91!taob
From: taob@pnet91.cts.com (Brian Tao)
Newsgroups: comp.sys.apple2
Subject: Re: AE 1.6 MB 3.5" drive
Message-ID: <263@generic.UUCP>
Date: 14 Dec 90 06:12:56 GMT
Sender: root@generic.UUCP
Organization: People-Net [pnet91], Etobicoke, ON
Lines: 25

From phs172m@vaxc.cc.monash.edu.au (Stephen Harker):

> The real difficulty, as I understand it, is that to get the so called
> 1.44Meg format (1.4Meg actually) you need the SWIM chip rather than
> the IWM on the GS motherboard.  This is why all the later Mac's went
> to the SWIM, and why it was included in the Mac SE upgrade.  Without
> the SWIM you can't write the appropriate disk format (MFM I think)
> needed.

    Aren't Smartport devices simply block storage devices as far as GS/OS is
concerned?  That is, it doesn't matter how big or small the device is, just as
long as the block size is 512 bytes.  I assume that is true since you can set
your RAM disk to anything you want and GS/OS won't mind.  So instead of
putting the SWIM chip on the GS, why not equivalent circuitry on the drive
itself?  It would return a volume size of 2880 blocks and any OS-level calls
should work fine.  Even low-level block reads and writes should work, as long
as the software uses Smartport calls.


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