[1] : The Free On-line Dictionary of Computing (27 SEP 03)

intel 486
     
         or "i486", "iapx 80486", and "intel dx4" but
        usually just "486".  a range of intel cisc
        microprocessors which is part of the intel 80x86 family of
        processors.
     
        the 486s are very similar to their immediate predecessor, the
        intel 80386dx.  the main differences are that the 486 has an
        optimised instruction set, has an on-chip unified
        instruction and data cache, an optional on-chip
        floating-point unit fpu, and an enhanced bus interface
        unit.  these improvements yield a rough doubling in
        performance over an intel 80386 at the same clock rate.
     
        there are several suffixes and variants including:
     
        intel 486sx - a 486dx with its fpu disabled see
        crippleware.
     
        intel 486dx - 486sx with a working fpu.
     
        486dx-2 - runs at twice the external clock rate.
     
        486sx-2 - runs at twice the external clock rate.
     
        486sl - 486dx with power conservation circuitry.
     
        486sl-nm - 486sx with power conservation circuitry; sl
        enhanced suffix, denotes a 486 with special power conservation
        circuitry similar to that in the 486sl processors.
     
        487 - 486dx with a slightly different pinout for use in 486sx
        systems.
     
        overdrive - 486dx-2 with a slightly different pinout for use
        in 486sx systems.
     
        rapidcad - 486dx in a special package with a companion fpu
        dummy package for use in intel 80386 systems.
     
        intel dx4, cyrix cy486slc.
     
        external clock rates include 16mhz, 20mhz, 25mhz, 33mhz,
        40mhz, although 16mhz is rare now, and the 20mhz processors
        are often clock doubled.
     
        the 486 processor has been licensed or reverse engineered by
        other companies such as ibm, amd, cyrix, and chips 
        technologies.  some are almost exact duplicates in
        specications and performance, some aren't.
     
        the successor to the 486 is the pentium.
     
        1995-02-21
     
     
see also:
intel cisc microprocessors intel 80x86 intel 80386 instruction set 
cache floating-point unit bus interface unit clock rate intel 486sx 
fpu crippleware intel 486dx rapidcad intel dx4 
cyrix cy486slc clock rates ibm amd 
chips  technologies pentium 

Intel Corporati >> I Words
Intel Corporati, definition of term: Intel Corporati
intel+corporati_pag1.html