Path: utzoo!utgpu!news-server.csri.toronto.edu!rutgers!uwvax!titanic.cs.wisc.edu!tonyrich
From: tonyrich@titanic.cs.wisc.edu (Anthony Rich)
Newsgroups: comp.sys.mac.misc
Subject: Edit 2.1:  In a heap of trouble?
Message-ID: <10566@spool.cs.wisc.edu>
Date: 8 Jun 90 09:11:40 GMT
Sender: news@spool.cs.wisc.edu
Organization: U of Wisconsin CS Dept
Lines: 68

THE EVIDENCE AND ACCUSATION.
I recently reported that Edit 2.1 was crashing reliably on my Mac II
under 6.0.5.  Others reported problems under 6.0.4, but it had worked
okay for me under 6.0.4.  On my machine, the crashes under 6.0.5 occurred
even if I turned off all inits using the Init cdev, and when it crashed,
my hard disk was rendered unbootable (but repairable using SUM II).

THE DENIAL.
However, I recently heard that another person WAS using Edit 2.1 reliably
under 6.0.5, on a IIci.  So I did some more testing.

THE INVESTIGATION.
I found that Edit worked fine when I booted from a floppy that had only
a minimal copy of System 6.0.5 on it.  So I put that new, virgin 6.0.5
System folder on my hard disk and started dragging the inits and cdevs
from my old System folder into it one at a time: Suitcase II, On Cue, etc.
After each addition, I rebooted and edited something with Edit 2.1 to see
if the newcomer caused Edit to crash.

Finally Edit began crashing again, but when I pulled the most recent
addition out of the System folder, Edit STILL crashed!  Then I noticed it
edited small files OK but crashed on larger ones.  I pulled more things
out of the System folder and then Edit could handle the larger files too.

THE NEW SUSPECT.
With some further experimentation I think I now see the problem.  (I'm not
all that familiar with Mac internals, so somebody please correct me if I'm
wrong.)  As I understand it, inits and cdevs occupy an an area of memory
called the system heap; apparently it's an area of limited size.  Edit 2.1
appears to start crashing when the addition of inits/cdevs reduces the
amount of free space in the system heap below some threshold.  It doesn't
seem to matter which inits/cdevs are in there; it's the amount of system
heap that's left over for Edit to use that matters.  And apparently just
"disabling" the inits/cdevs doesn't do the trick, you have to actually
remove them from the System folder.

I did a "Get Info" on Edit and saw that its suggested and actual application
memory size (not the same thing as the system heap size) was 224K; hoping for
the best, I tried increasing that to 512K, and for a while I thought that
fixed things, but it didn't; I still got crashes.

SOLVING THE CRIME.
Over in comp.sys.mac.system, someone mentioned that if you buy Disktop,
you also get a program called HeapFixer which allows the maximum size of
the system heap to be increased.  Another user reported that after using
HeapFixer nearly all of his system bombs went away.  But many of us won't
want to buy Disktop just to get HeapFixer.  Someone also said they thought
HeapFixer was available separately through some user groups with the
permission of CE Software.

1.  Can anyone confirm whether HeapFixer is available separately
    (hopefully free) with CE's blessing, and if so, where it's available?
    Could it be posted to the sumex and Rice archives?

2.  Does anyone know of an easy way to increase the size of the system
    heap, like using ResEdit to change its maximum size somewhere?

THE CONFESSION.
I got Edit 2.1 from a local PD/Shareware collection a LONG time ago
and have been using it gratis, but I understand now that it is copyrighted
and sold by Consulair.  If someone would send me Consulair's address,
I'd like to make restitution.  (I *do* pay for the shareware and commercial
software I use.  It's harder on the wallet but easier on the conscience. :^)
--
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| EMAIL:  tonyrich@titanic.cs.wisc.edu  | 
| Disclaimer:  I speak only for myself. |
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