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From: tony@tui.marcam.dsir.govt.nz (Tony Cooper)
Newsgroups: comp.sys.mac.system
Subject: virtual memory arithmetic puzzle
Message-ID: <1991May22.235626.26064@am.dsir.govt.nz>
Date: 22 May 91 23:56:26 GMT
Sender: news@am.dsir.govt.nz
Reply-To: sramtrc@albert.dsir.govt.nz
Organization: Applied Mathematics Group D.S.I.R.
Lines: 19

I have a Mac II, FDHD ROMs, no floppy drives (broken), PMMU, 20MB RAM, 2
Nubus cards. Under system 7 memory control panel I do not get the 32 bit
option (the ROMs need a wash).

The Finder says I have 20MB memory of which 6MB is free. I expected this
to be 20MB with about 13MB free. Why not? Why do people with just 8MB RAM
get more virtual memory than me?

When I try to turn on virtual memory, it says 20MB memory, 8MB free disk
space - not enough disk space. Why not enough? Why does disk space have
to match RAM space? I would have expected RAM+DISK=total memory available.

If x=RAM and y=DISK then total memory available should be x+y right? Why
does y have to be >= x?

Strange stuff.

Tony Cooper
sramtrc@albert.dsir.govt.nz