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From: dvmark@cca.UUCP
Newsgroups: comp.sys.amiga
Subject: Re: Track 40 Blues SOLVED!!!!!  Delay() is the culprit!
Message-ID: <13886@cca.CCA.COM>
Date: Wed, 11-Mar-87 11:13:15 EST
Article-I.D.: cca.13886
Posted: Wed Mar 11 11:13:15 1987
Date-Received: Sat, 14-Mar-87 11:46:25 EST
References: <8703070244.AA13483@cory.Berkeley.EDU>
Reply-To: dvmark@CCA.UUCP (Mark Jay Jones)
Organization: Computer Corp. of America, Cambridge, MA
Lines: 29
Summary: Doomed to repeat it

In article <8703070244.AA13483@cory.Berkeley.EDU> dillon@CORY.BERKELEY.EDU 
(Matt Dillon) writes:
>	You are GUARENTEED to get a disk write error!
> (goes on to explain that Delay(0) causes the problem)
>	So far as I can tell, Delay(1) doesn't seem to cause any problems.
>					-Matt
In (an old) article (?@trantor.UMD.EDU) louie@trantor.UMD.EDU (Louis A.
Mamakos) writes:
> (about his new improved version of GfxMem)
> The display updating is now much more crisp, and I'm now using the
> timer.device rather than the AmigaDOS Delay() subroutine.  There was a
> note that the previous version could trash a disk while running the READ
> (a primative downloading program - MJJ) program.  I tested the new version
> while downloading a copy of GfxMem.c (...), and things seemed to run just
> fine.
Those who learn nothing from history are doomed to repeat it
  - Santayana
Those who have heard Santayana's quote are doomed to repeat it
  - Anon
The above excerpt from Mr. Mamakos is dated 28 November, 1985!
                                                         ^^^^
This note came with all copies of GfxMem that I have seen (on Fish Disks, BCS,
etc.), maybe we should copy more working code than reinventing it.

One thing that I am unclear about.  The GfxMem problem was with a non-zero
number sent to Delay(), keeping in mind that this was also AmigaDOS 1.0.
If Delay(0) is still causing problems, I wonder if Delay(>0) just has a 
smaller target to hit, but the same possibility of hosing disk tracks?  Matt,
could you run some extensive tests with Delay(>0)?