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From: umapd51@sund.cc.ic.ac.uk (W.A.C. Mier-Jedrzejowicz)
Newsgroups: comp.sys.handhelds
Subject: Re: Mysterious partial loss of 48SX memory
Message-ID: <1990Aug1.002453.1548@cc.ic.ac.uk>
Date: 1 Aug 90 00:24:53 GMT
References: <5935@videovax.tv.tek.com>
Sender: news@cc.ic.ac.uk (USENET News System)
Reply-To: umapd51@cc.ic.ac.uk (W.Mier-Jedrzejowicz)
Organization: Imperial College Computer Center, London, UK
Lines: 21
Keywords:LAST
Summary:No, it's not mysterious.


Bill McFadden worries that he had only 3k of HP48 memory left when he
was using a 7k object and should have had 10k left. The most likely
explanation then is that a spare copy of the 7k object was lurking
around somewhere. Now, the HP48 keeps spare copies of things in the LAST
STK, LAST ARG and LAST CMD areas. That could be up to 3 copies of the
object! When Bill did a self-test, the full 10k returned. That's
obvious, the stack and the LAST everything areas are cleared out during
a self-test, so the spare copy, wherever it was, got cleared out. All is
explained, unless Bill is sure that he had LAST STK, LAST ARG and LAST
CMD disabled - did you, Bill?
As for the low battery message,  I'd say that was purely coincidental,
since the above explains the missing 7k completely.
Moral: be aware that the LAST options can take up a great deal of memory
in the HP 48SX. Be careful though before disabling them, as it can cost
you an awful lot of effort recreating something because you disabled all
these options.
Wlodek Mier-Jedrzejowicz, Space & Atmospheric Physics, Imperial College,
London.
DISCLAIMER: On this occasion my HP48 shares my opinion, but neither my
employer nor HP even know about it.