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From: smsmith@hpuxa.acs.ohio-state.edu (Stephen M. Smith)
Subject: Re: Question about different 386's ...
Message-ID: <1991Apr5.213536.12925@magnus.acs.ohio-state.edu>
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Date: Fri, 5 Apr 1991 21:35:36 GMT
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c60b-1eq@e260-1f.berkeley.edu (Noam Mendelson) writes:
akcs.gregc@vpnet.chi.il.us (*Greg*) writes:
>>Takis Skagos scribbled:
>>>  Hi.  I've a question about the different chips in the 80386 family
>>>tree.  I've heard the 386 refered to as 386SX, 386DX, and something
>>>else that I cannot remember.  Does anybody out there know?
>>Hi too.. The 80386 is very simple.  386SX is a 16 bit crunching chip.  It
>>processes 16 bits at a time while the 386DX is a 32 bit crunching chip.  You
>>are probably better off to get the DX.  But for tight bugets; an SX is the
>>way to go.
>
>I disagree.  Even though the DX has 16 more pins, most of the time they're
>not being used.  This is due to the fact that most MSDOS programs are 16-bit
>(with the exception of 386-specific programs).  So unless you actually make
>use of all 32 pins, a 386SX is not a bad way to go.

Hmmm.....  Maybe a bit of clarification is needed:

SX and DX chips are both 32-bit processing chips.  BOTH will
run 386-specific programs, DOS or otherwise.  The number of
external pins on the SX does not affect its being a true
386 processor, nor do they make it incompatible with
32-bit "protected" mode software.

The difference in the two chips is that the DX can access anything
EXTERNAL to the chip via a true 32-bit channel, whereas the SX
accesses external things via a 16-bit channel.  This includes
memory, peripherals, or whatever else.

Also, most MSDOS programs are not 16-bit.  They are 8-bit.  How
else do you think I've been running them on my XT??????

Steve Smith
