Path: utzoo!utgpu!news-server.csri.toronto.edu!rpi!think.com!zaphod.mps.ohio-state.edu!mips!dimacs.rutgers.edu!rutgers!cbmvax!daveh
From: daveh@cbmvax.commodore.com (Dave Haynie)
Newsgroups: comp.sys.amiga.hardware
Subject: Re: Amount of chip memory is different each time I boot, what's the deal?
Message-ID: <21997@cbmvax.commodore.com>
Date: 29 May 91 16:00:09 GMT
References: <1991May26.064123.18564@news.iastate.edu>
Reply-To: daveh@cbmvax.commodore.com (Dave Haynie)
Distribution: na
Organization: Commodore, West Chester, PA
Lines: 26

In article <1991May26.064123.18564@news.iastate.edu> skank@iastate.edu (Skank George L) writes:
>Hello folks.  My A3000 is exhibiting a phenomenon that seems strange to me.
>I recently had 4Megs of memory added.  The origional 1Meg of memory is now
>in chip ram, bringing the total chip ram to 2Megs.  Here's the problem,
>each time I boot the machine I get a different amount of chip ram available.
>Usually it's about 900K, which is what I had before the upgrade.  Sometimes
>I get 1.1, 1.4, and as much as 1.9Megs of chip ram available.  What's going
>on?  

Sounds to me like you have at least one flakey chip.  That's not necessarily
a bad chip, you might have one with a bent-under pin, or other such atrocity.
Basically, as I understand it, when Exec wakes up from a cold boot it goes
out and calculates how much Chip RAM is available, on a reasonably fine grain
(maybe 64K or 128K chunks).  It doesn't really expect to find flakey Chip RAM.
So in testing memory, it'll most likely go until it finds a chunk that doesn't
test out.  If you're not crashing, this indicates that the first meg is still
fine, and that you never get to the second meg.  That's actually a good sign,
as it indicates that nothing is likely being shorted out and you _probably_
don't have a severely dead chip, as these things tend to drag down the whole
chip bus.  You should have that second bank of Chip RAM looked at carefully. 

>George L. Skank			|Fast cars, fast women, fast computers...   ///
-- 
Dave Haynie Commodore-Amiga (Amiga 3000) "The Crew That Never Rests"
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      "That's me in the corner, that's me in the spotlight" -R.E.M.