From: cummings@tiger1.prime.com (Kevin J. Cummings)
Subject: Re: Minimum requirements for linux - just to run single user
Keywords: Minimum requirements
Organization: Prime Computer, Inc.
Date: Wed, 2 Sep 1992 18:16:34 GMT

In article <data.715428938@cs1.bradley.edu>, data@cs1.bradley.edu (Mark Hall) writes:
> In <1992Sep1.135811@tiger1.prime.com> cummings@tiger1.prime.com (Kevin J. Cummings) writes:
> 
> >Er, Ah, is it a SigmaSigma step chip?  or does it have the infamous task switching
> >bug in it?  If its a REALLY old 386, you may not be able to use it.
> 
> I am not aware of a task switching bug...:)  I've run Desqview with no
> problems.  I just don't like it. :)  SigmaSigma step chip?  I am not familiar
> with that.

There was a bug in the early 386 processors (someone will correct me, I'm sure,
if I don't get the little details right) that caused a problem in protected mode
(so DOS users never saw it!).  I thought it was related to task switching, but
it might have been related to to the floating point co-processor.  Intel fixed
the bug in a version of the 386 they called the SigmaSigma step.  Look at your
386 ship.  If it has 2 Sigmas on it, you have the fixed version.  If you don't,
and you have an OLD chip, then you potentially will have problems running that
ship in protected mode.  After the SigmaSigma chip, Intel started in with the
DX/SX naming convention.  I would be wary of any non-xX 386 without the SigmaSigma
printed on it for protected mode applications.

> >> ram.  (Ok...You can stop laughing now... :)  Should I assume that ...
> >Whose laughing?  My Dad has my old 16MHz 386 DX with 1MB of RAM.  640K conventional
> >and 384K extended?  Do you have ANY extended memory?  Or is it configured as
> >BIOS shadow RAM?
> 
> No.  I have NO extended.  Just conventional 640 K.  Really sucks.

Bummer.  Sounds like a 286 (or 8088) motherboard minimally extended to support
a 386 running DOS, period.  How bogus!  (Don't feel too bad, I GAVE my 16MHz
386 to my Dad because it would have cost me $800 to upgrade from 1MB to 4MB
of memory (with NO chance of ever upgrading beyond that.  Instead I bought my
25MHz motherboard for $1300 (with 4MB of ram!).  Then memory prices started to
fall.)

> >> Linux?  I'm hoping to be able to upgrade to at least 2 megs sometime, but am
> >In order to upgrade a 1MB 386 to 2MB, you have to be able to add in 4 banks of
> >256K memory.  386 memory must be 32 bits wide unless you have an SX system,
> >in which case it must be 16 bits wide.  Since most memory banks are 8 bits wide,
> >you either need space for another 4 banks on your motherboard or on a 32bit
> >memory card.  If you only have space for 4 memory banks, then you will need
> >to upgrade them from 256K chips to 1M chips, increasing your memory from 1MB to
> >4MB.
> 
> Not sure what my chips are.  I'll probably just buy a 32bit expansion card.
> There's no room on the motherboard for expansion (my motherboard is just a
> bus) and the memory is a card...Stupid...Same for Processors, and I/O stuff.

Sounds a lot like my old S-100 machine B^).

> >> 	D*mn. Mem swap error (or something like that).
> 
> >Sounds like 1MB is too little memory.  I have heard of people running in 2MB
> 
> Yeah...I found out in the FAQ (somebody was nice enough to mail it to me...:)
> Thanks! that it requires 2M just to boot.  ALso, several people have made
> suggestions on the amount of memory and HD space to make available to linux.
> I've got a rough idea of the system I need to do that...:)

Ted's message says there might be hope if you had as little as 384K of extended
memory.  Sounds like you're SOL.   Sorry.

> >on 386SX processors.  Just be sure to configure a swap partition (4-8MB) to
> >get you running.  As long as there is sufficient memory to run the kernel in,
> >swap space will look like paged virtual memory to your system, and it will
> >manage it for you.  I have 4MB ram, and 10MB swap.  I haven't run out of memory
> >yet.  I suspect you could run with 2M ram and 4 MB swap, but it would be slow.
> >(Lots of disk accesses I suspect.)
> 
> Probably.  Couldn't be worse than on our AT&T 3b2 (ugh! :)

Oh yeah, I've heard of those machines!  There the ones that ran out of clock bits
for the year in 1992!  Great foresight in hardware design!

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Kevin J. Cummings                       PrimeService
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					Framingham, Mass.
Work:  cummings@primerd.Prime.COM
Home:  cummings@kjc386.framingham.ma.us

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