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From: camm@els.ee.man.ac.uk (Ian Camm)
Newsgroups: comp.sys.atari.st
Subject: Re: More than 4 Meg ??
Message-ID: <2642@m1.cs.man.ac.uk>
Date: 6 Jun 91 15:16:54 GMT
Article-I.D.: m1.2642
References: <91154.141443SYSPMZT@GECRDVM1.BITNET> <1991Jun4.112631.10649@cs.nott.ac.uk> <3153@odin.cs.hw.ac.uk> <1991Jun5.222630.24777@jato.jpl.nasa.gov>
Sender: news@cs.man.ac.uk
Organization: Manchester Computer Centre, University of Manchester UK
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In article <1991Jun5.222630.24777@jato.jpl.nasa.gov> vsnyder@jato.Jpl.Nasa.Gov (Van Snyder) writes:
>In article <3153@odin.cs.hw.ac.uk> neil@cs.hw.ac.uk (Neil Forsyth) writes:
>>In article <1991Jun4.112631.10649@cs.nott.ac.uk> dpg@cs.nott.ac.uk
>>(Dave Gymer) writes:
>>> ... I believe, that the MMU in the STe can
>>>only handle .25 and 1 meg SIPPS/SIMMS, and these are arranged in two banks,
>>>which must contain the same amount (hence, memory configurations can only
>>>be .5 meg, 1 meg, 2 meg, 2.5 meg, and 4 meg). I too have a four meg STe.
>>                          ^^^^^^^
>>
>>Nope. TOS 1.6 has a screwed up memory sizer that assumes that if two banks of
>>RAM exist then both banks are the same size. I don't know if this is a bug
>>in the true sense or malicious crippling but it is sad.
>>
>>BTW, a bank is two SIMMs since memory access is on a word basis.
>>
>>	512K	= 2 x 256K SIMMs
>>	1Mb	= 4 x 256K SIMMs
>>	2Mb	= 2 x 1Mb SIMMs
>>	2.5Mb	= 2 x 1Mb SIMMs + 2 x 256K SIMMs (Not with TOS 1.6)
>                  ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
>I heard this works on TOS 1.6 if you put the 256k SIMMs as the first bank
>and the 1M SIMMs as the second bank.  But I could be wrong.  If you're
>having trouble, though, it's trivial to try it the other way.
>>	4Mb	= 4 x 1Mb SIMMs

	Well 2.5Mb does work on my 520STE with TOS 1.6, but it does think there
are 4Mb there. I have not had any problems yet but I have not (knowingly)
tried to use all of the memory thus far. I have the feeling that when I
do I will commit mass bit murder :-) by trying to throw them into spaces that
aren't there. I will try changing the boards round and let you know what
happens.

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Cheers,

Ian

--
Ian Camm                           | JANET: camm@uk.ac.man.ee.els
Dept. of Electrical Engineering    | ARPA:  camm@els.ee.man.ac.uk
University of Manchester, England  | UUCP:  ...!!ukc!man.ee.els!camm
Disclaimer: If you think I need one make it up yourself.