NetNews Usenet Archive 1993 #3/NN_1993_3.iso/spool/bionet/software/2526

Internet Message Format | 1993-01-25 | 1.9 KB

Path: sparky!uunet!biosci!MAYO.EDU!penniston
From: [e-mail]
Newsgroups: bionet.software
Subject: Re: Re: PC80486
Message-ID: <[e-mail]>
Date: 25 Jan 93 20:00:15 GMT
Sender: [e-mail]
Distribution: bionet
Lines: 49


!In article <[e-mail]>,
![e-mail] (Kirk Schnorr) writes:
!|> I was wondering if anyone out there could inform me about the relative
!|> differences between the various flavors of 486 CPU chips in PC
!|> computers.  We are about to buy a new system for data aquisition and
!|> proccessing for our HPLC to replace our slow and failing HP Vectra 286.
!|>     We were thinking to get a 486SX based machine since it is the
!|> cheapest but I do not want to sacrifice a built in  math co-proccessor
!|> or 32 bit data path it the 486SX is missing these.  Can anyone enlighten
!|> me?

!My understanding of the various members of the Intel 80386 and 80486 families
!are as follows:
!
!Chip        Internal    External    Floating
!Designation    Data Path    Data Path    Point Unit?
!-----------    ---------    ---------    -----------
!386DX        32 bits        32 bits        No
!386SX        32 bits        16 bits        No
!
!486DX        32 bits        32 bits        Yes
!486SX        32 bits        16 bits        Yes
!
!Please note that Intel uses the "SX" designation to denote the narrower
!external data path, NOT the presence or absence of a math coprocessor.


    I don't think this is quite right, since Intel has used their chip
names in a rather confusing way recently.  As I understand it, the correct
table should read as follows:

Chip        Internal    External    Floating
Designation    Data Path    Data Path    Point Unit?
-----------    ---------    ---------    -----------
386DX        32 bits        32 bits        No
386SX        32 bits        16 bits        No

486DX        32 bits        32 bits        Yes
486SX        32 bits        32 bits        No

    As you can see, Intel changed the meaning of "SX" between the 386
and 486 chips.

            John Penniston
            Biochem. & Mol. Biol.
            Mayo Clinic
            [e-mail]