glf@sppy00.UUCP (HILL GREGORY L.) (08/07/90)
Well, thanks to all who responded to my questions about the SUM II method
of System Heap size fix.
Just to wrap up, here's what I've learned ( and [DISCLAIMER COMMING!]
note that a lot of this is just my guessing, so it could be wrong ... )
When the system is first loaded, it allocates a default heap size.
This size is recorded as part of the information contained in the boot
blocks. As INITs are loaded, they are assigned pieces-parts of the heap
space, until that initial space if full. All INITs loaded after that
cause the system to dynamically allocate space for each, but ONLY enough
to satisfy the request ... hence no spare work space for later.
If the About Finder box shows, say, 800K used then 800K of memory IS being
used, no matter what the initial space was. To give yourself free space,
you'll have to increase the initial heap enough to allow for the 800K (or
whatever) needed PLUS the empty work space (or 1.25*800K = 1 Meg, in this
case).
No problem if you've go the RAM!
Another thing I learned was that, when using SUM II to change the heap
size, you don't need to use the "Write Boot Blocks" menu option after
changing the size. I guess this is a misleading name ... apparently it
writes DEFAULT values (but fortunately leaves the heap size alone).
So all you need to do is "Edit Boot Blocks", change the size, press
the CHANGE dialog button, and you're done.
Hope this helps someone, thanks for the help from those who responded, and
most of all, don't forget my disclaimer :-=)
========
Greg
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Greg Feldman-Hill {seismo|cbosgd}!osu-cis!sppy00!glf -OR- gfh@rsch.oclc.org
OCLC - Online Computer Library Center ... Dublin, Ohio
"If one studies too zealously, one easily loses his pants." A. Einstein