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From: gersh@aplpy.jhuapl.edu (John R. Gersh)
Newsgroups: comp.sys.mac.system
Subject: Problem with startup screens and Sys 7.0 VM
Message-ID: <1991May23.211636.21537@aplcen.apl.jhu.edu>
Date: 23 May 91 21:16:36 GMT
Sender: news@aplcen.apl.jhu.edu (USENET News System)
Distribution: usa
Organization: Johns Hopkins University Applied Physics Lab
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I've noticed an apparent problem when trying to use a startup screen under
System 7.0 with virtual memory turned on.

Configuration: Mac IIcx, 5M RAM, Apple 80M internal drive (with 6.0.5), Apple
40M external drive (with 7.0). A startup screen document is present at the
top level of the 7.0 System Folder. VM on, 8M total.

Symptom: On booting, just after the startup screen is drawn, the machine
crashes with a bomb dialog saying:
	
	Not enough memory available while using
	[Blank line here]
	To temporarily turn off extensions, restart and hold down the shift
	key.

This situation occurs repeatably, even with no extensions of any kind 
present. Startup screens appear to work fine under System 7.0 with VM off.

I tried a startup screens made by different applications (Giffer 1.08,
MacPaint 2.0) and made one as small as I could (about 25K); the result was
the same.

I suppose that this should not be too surprising. Startup screens need to
allocate some memory early in the boot process; evidently this is not
entirely compatible with setting up the VM memory mapping.

Interesting Note: When I first tried to use a startup screen, under 7.0 where
did I put it? In the Startup Items folder, of course; where else would it go?
Of course, this resulted in the screen _document_ being opened by the
application that created it after the boot process was over. That's what the
Startup Items folder is for, after all! If it's to work in the normal way
(with VM off, apparently), the startup screen needs to be at the top level of
the System Folder

						- John Gersh

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