Path: utzoo!yunexus!maccs!cs4g6ag
From: cs4g6ag@maccs.dcss.mcmaster.ca (Stephen M. Dunn)
Newsgroups: comp.sys.ibm.pc
Subject: Re: 286 clone
Keywords: clone, 286, pc
Message-ID: <25570949.7649@maccs.dcss.mcmaster.ca>
Date: 7 Nov 89 16:56:41 GMT
Article-I.D.: maccs.25570949.7649
References: <112@oiscola.Columbia.NCR.COM>
Reply-To: cs4g6ag@maccs.dcss.mcmaster.ca (Stephen M. Dunn)
Organization: McMaster University, Hamilton, Ontario
Lines: 43

In article <112@oiscola.Columbia.NCR.COM> salmassr@oiscola.Columbia.NCR.COM (Samer Almassri) writes:
$Any recommendations (along with names of reliable dealers) are most
$welcome.  

   My AT clone uses a Suntac motherboard (including the Suntac chipset).
I haven't had any problems with it.  It allows for up to 4M on the motherboard
(512K/640K/1M/2M/4M; you can use the memory above 640K either as extended or
as expanded memory); it's a baby-size board with eight expansion slots (I don't
recall how many are 16-bit and how many are 8-bit); it runs at 8/12 MHz, though
they may have upgraded this since then.

$Also what is what is the difference between static and dynamic RAM?
$Which one is usually used any why?

   Several differences.  Static RAM will maintain its contents as long as
you keep the power turned on.  Dynamic RAM has to be read periodically (and
we're talking several times a second here) or it forgets its contents; this
is accomplished automatically by circuitry somewhere on your motherboard
and is known as "refresh".  This is due to the design of the cells used to
store each bit.  Static RAM uses a much more complicated cell which is
essentially a flip-flop; dynamic RAM uses a much simpler cell.  Therefore,
you get more dynamic RAM on one chip than you can with static, and this is
why Dynamic is used.  Lower costs and less packages for a given amount of
memory.

   Also, dynamic RAMs typically have multiplexed addresses, where you have
to feed it the address in two chunks, whereas static RAMs usually have just
one.  This makes dynamic RAM a fair bit slower than static.  Therefore,
in machines with caches, typically the main memory is dynamic and runs
with at least one wait state, while the cache memory is static and runs
without wait states.

   There have been clones with all static memory (I remember seeing one
advertised that was a 386 clone, probably 16 MHz, that advertised 1M of
static, no-wait-state memory); however, these are pretty rare (Howie, don't
tell me you have one of these, too :-)


-- 
Stephen M. Dunn                               cs4g6ag@maccs.dcss.mcmaster.ca
          <std_disclaimer.h> = "\nI'm only an undergraduate!!!\n";
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They say the best in life is free // but if you don't pay then you don't eat