Path: utzoo!mnetor!uunet!husc6!bbn!uwmcsd1!csd4.milw.wisc.edu!devilbis
From: devilbis@csd4.milw.wisc.edu (Vilbiss Warren C De)
Newsgroups: comp.sys.amiga
Subject: Re: AmigaDos don't thrash no more!
Message-ID: <4699@uwmcsd1.UUCP>
Date: 19 Feb 88 13:35:50 GMT
References: <8504@sunybcs.UUCP> <3247@watcgl.waterloo.edu> <8626@sunybcs.UUCP> <33989UH2@PSUVM>
Sender: daemon@uwmcsd1.UUCP
Reply-To: devilbis@csd4.milw.wisc.edu (Vilbiss Warren C De)
Organization: University of Wisconsin-Milwaukee
Lines: 29
Summary: You're missing the point!

(message being posted by Mike Shawaluk)

In article <33989UH2@PSUVM> UH2@PSUVM.BITNET (Lee Sailer) writes:
>In article <8626@sunybcs.UUCP>, ugpete@sunybcs (Peter Theobald) says:
>>
>>In article <3247@watcgl.waterloo.edu> bmacintyre@watsol.waterloo.edu (Blair MacIntyre) writes:
>>>In article <8504@sunybcs.UUCP> ugpete@sunybcs.UUCP (Peter Theobald) writes:
>>>>
>>>> <lots of stuff about disk thrashing>

Hey, guys, I'm no expert on the subject of optimized disk seeking algorithms,
but it seems to me that a half-way decent disk caching program would just
about eliminate the majority of the thrashing that everyone's been talking
about!  For example, two programs are each trying to read from tracks 5 and
75 respectively; when the first read takes place from track 5, the entire track
would go in the cache; then the second program goes to track 75 & reads.  Then,
when program #1 wants data from track 5 again, it gets it out of the cache, and
the head doesn't have to move!  Now, I will be the first to admit that there
are a few holes in my example that need plugging; for example, these two 
programs probably aren't going to be reading JUST tracks 5 and 75, but possiblu
several tracks each, and they aren't going to be necessarily in contiguous
order.  Also, my example only covers reading files, not writing, which is 
another case altogether.  But, anyone out there who's ever used FACC or FACC II
will atest to the improvements in floppy disk performance that are achieved.
All in all, the best $21.00 (from Abel) that I've spent on my Amy so far!
  - Mike Shawaluk
  {sorry, no fancy signature yet!}

order.  Also, the