Path: utzoo!attcan!uunet!seismo!sundc!pitstop!sun!decwrl!ucbvax!UIAMVS.BITNET!AWCTTYPA
From: AWCTTYPA@UIAMVS.BITNET ("David A. Lyons")
Newsgroups: comp.sys.apple
Subject: GS and 5.25 disks
Message-ID: <8903080649.aa02727@SMOKE.BRL.MIL>
Date: 7 Mar 89 23:40:00 GMT
Sender: daemon@ucbvax.BERKELEY.EDU
Organization: The Internet
Lines: 43

>Date:         Tue, 7 Mar 89 18:32:41 GMT
>From:         Stdnt 42
>              <mailrus!uflorida!haven!aplcen!jhunix!c08_d042
>              @TUT.CIS.OHIO-STATE.EDU>
>
>This discussion brings something to mind. There's ways to check to
>see if there's a disk in a 5.25" drive so that it *doesn't* slamm the
>r/w head. Most well written games and older utilities (like create
>with garfield) used it. It only takes about 3/4 second, or faster
>even, to find if there is a disk in the drive ready to be read. [...]
>It requires custom routine, however, since Pro[DOS] uses the retard
>method.  If Pro[DOS] did it this way tho...nobody would be bitchin
>about 5.25" drives not being suitable for gs's.
>
>Chris Coleman    c08_d042@jhunix

If ProDOS and/or the GS/OS APPLEDISK5.25 driver used a method like
that, people would be complaining that sometimes their system refused
to recognize their good 5.25 disks.  Why?  Because there's no way to
guarantee that the drive's read/write head is actually at a valid
track.  _Especially_ if the last thing you did with the drive was
play a copy-protected game or access a nonstandard disk with more
than 35 tracks, that method could incorrectly decide there was no
disk.

What you call the "retard method" I call a method that always works.

Anyway, 3/4 of a second is still far too long for the Finder to poll
the 5.25 drives the way it does for 3.5 drives (and presumably for
_any_ removable-media devices with GS/OS drivers that can report
whether media is present).  The Finder polls about twice a second.

I never said 5.25 drives weren't suitable for GSs, but they aren't
nearly as much fun.  I have two and use them--but mostly to copy
disks to send to people with no 3.5" drives.  3.5" disks store 5.7
times as much data (800K/140K) for about 3 times the price
($0.79/$0.25 from MEI).  And, of course, access to the 3.5s is
faster, and the disks are sturdier.

 --David A. Lyons              bitnet: awcttypa@uiamvs
   DAL Systems                 CompuServe:  72177,3233
   P.O. Box 287                GEnie mail:    D.LYONS2
   North Liberty, IA 52317     AppleLinkPE: Dave Lyons