In article <1993Jan25.170138.10928 at welchgate.welch.jhu.edu> ken at oscar.welch.jhu.edu (Ken Fasman) writes:
>In article <1993Jan25.090410.12066 at gserv1.dl.ac.uk>, schnorr at tournesol.versailles.inra.fr (Kirk Schnorr) writes:
>|> 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
>>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.
This isn't always true. The 486SX has a disabled floating point unit. The
upgrade chips (Overdrive) for these machines disable the original CPU when they
are installed (They have an enabled FPU). I believe that the 486SX retains a
32-bit external data path.
J. Pablo Abonia
University at Buffalo BITNET: pablo at sunybcs.BITNET
Roswell Park Cancer Institute Internet: pablo at cs.Buffalo.EDU