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From: GR.MRB@isumvs.iastate.edu (MARK BERAN)
Newsgroups: comp.sys.zenith
Subject: Re: RAM simms
Message-ID: <1991Feb15.175232.13497@news.iastate.edu>
Date: 15 Feb 91 17:52:32 GMT
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Organization: Iowa State University, Ames IA
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In article <1991Feb15.020037.29706@news.nd.edu>,
mandell@mozart.helios.nd.edu (Dan Mandell) writes:
>Do the newer Zeniths require special Simms?  What's different about
>Zenith's memory access?
>
>
Zenith machines do not use any SIMMs that could be called unusual.
I did read an article in some journal or other that listed Zenith
amoung a hand-full of companies who used non-standard memory in an
attempt to keep selling their own over-priced memory.  That just
isn't true.

The Zenith 248/12, 286LP/8, 286LP/12, LP+, 386SX-16, and 386SX-20
all use common 256Kx9-bit and 1Mx9-bit 80ns SIMMs, available from
literally thousands of sources.  Be careful though.  Some of those
sources really aren't very good.  I generally recommend purchasing
what is called 'major-on-major' brand SIMMs unless you know and
have tested SIMMs from the source you are buying from.  The term
'major-on-major' simply refers to major brand chips (ie: Toshiba,
NEC, Hitachi, Okidata, etc) mounted by and on SIMM boards of the
same make.  The boards vary wildly from other sources.

The Zenith 386/20, 386/25, 386/33, 386/33E, and I believe the new
486/25 all use what are becomming very common, 256Kx36-bit (1M)
and 1Mx36-bit (4M) 80ns SIMMs, available not from thousands of
sources, but certainly from hundreds.  They are basically the same
SIMMs which IBM, HP, AST, and others are using.  The only known
catch is that they really should be purchased as 'major-on-major'
yet since the technology seems somehow to have eluded many of the
local SIMMs assemblers.  Prices have been higher, but even that
has changed so that they are very near the price of 9-bit SIMMs.
The nice thing about them is that because they are 36-bits wide,
they can be added in onesies instead of 2 or 4 at a time as is
required by most 16-bit and 32-bit machines.  In 386 Zeniths, the
first 4 SIMMs must be of the 256Kx36 variety.  The remaining 4
can be either 256Kx36 or 1Mx36.  In the new 486, it is recommended
that the SIMMs be installed in pairs of 2 to maintain the memory
interleaving.

Mark