6/12    What's the difference between a 386DX and a 80386?  I have a "386(TM)DX
        Microprocessor Programmer's Reference Manual" and a "80386 Programmer's
        Reference Manual", but they list different cycle counts for the same
        instruction.
        \_ It's the exact same thing.  One of your manuals is wrong.
        \_ 386DX is the "Deluxe" version of the 80386
           \_ Hmm, so the "Deluxe" requires more cycles?  "REP MOVS" is 8+4*CX
              cycles on the 386DX but 5+4*CX on the 80386?
                \_ No one ever accussed the Intel x86 designers of doing things
                   that made sense.  Just look at the whole segmented memory
                   nightmare.
           \_ 386SX is the "SuX" version of the 80386
        \_ I vaguely remember one has the co-processor built-in and the
           other doesn't.  But then, my memory is pretty faulty these days.
        \_ http://aol.pcwebopedia.com/TERM/I/Intel_microprocessors.html
           BTW, it was the 486SX that didn't have a co-processor.  80386's
           never had them.
                \_ just don't mention anything like this when Kahan is around
           \_ 486SX had an 8-bit bus, whereas the DX has a 16-bit bus.
              \_ I'm sorry, but that was an incorrect answer.
        \_ a 386DX is an 80386DX without the annoying 80 part.
        \_ a 386DX is, in fact, a .25 micron copper-process 68030
           \_ so what's a 386SX?
              \_ .30 micron aluminum
              \_ .44 magnum
                 \_ *giggle*
                 \_ Or maybe it is a .8 CMOS -eric
        \_ the 386DX is the 80386, as god intended it to be. the DX
           to distinguish it from the later, lamer 386SX which is a
           386 crippled with a 16bit data bus (as opposed to 32 on the DX).
           Both are essentially programatically identical. To confuse
           matters further, there was a 486DX (normal) and 486SX but
           the difference there was that the former had a built-in maths
           coprocessor and the latter did not. Bus widths were the same.
           \_ And there's a 486GX with 16-bit data bus.
           \_ Then how come the manuals of 386DX and 80386 shows different
              cycle counts for "REP MOVS"?
                \_ Why do you care?  No one uses 386's anymore and the timings
                   on modern CPUs are far different.
           \_ Didn't the 486SX actually have the coprocessor on-chip but
              was disabled by an extra pin?
        \_ speaking of processors, what distinguishes a 0.18 and a
           0.25 micron processor (such as when some articles discussing
           the dreamcast processors chips vs. the upcoming ps2 processor
           chips?  the 0.18 is supposed to be better than the 0.25
           but harder to manufacture...what makes the 0.18 better, what
           does that number refer too?   -- no-clue
           \_ 0.18 and 0.25u refers to the minimum channel length of a
              transistor.  Obviously, the shorter the channel length,
              the less resistance there exists in the pull up and pull
              down network of a CMOS circuit.  Changes in process
              technology also effects other factors like the reduction
              of gate oxide thickness which increases the gate capacitance
              per area of transistor and, therefore, increases the gain
              as a result of applying gate voltage.  Also, among many
              other things, the threshold voltage changes.  Take 105
              or 141 and they'll tell you all about it (but by all
              means, avoid Neureuther). -jeff
                \_ Width of 'wiring'.  Smaller = less heat from lower
                   resistence but harder to make.  Less heat = can run
                   faster before dying from heat problems.
                       \_ thanks, i didn't know what that number referred to.