XPost: comp.os.ms-windows.misc, alt.windows7.general, microsoft.   
   ublic.windowsxp.general   
   From: TimSlattery@utexas.edu   
      
   "J. P. Gilliver"  wrote:   
      
      
   >For 386 and 486, the confusingly changed what "SX" and "DX" meant; on   
   >one (I forget which), SX meant it _didn't_ have a floating-point maths   
   >co-processor on board, DX meant it did. On the other, SX meant it had a   
   >half-width (so 16?) bus outside the chip (so requiring two fetches to   
      
   The 486 was the first Intel chip to have the numeric coprocessor   
   onboard. Intel wanted to prese4ve the "SX" price point, so they   
   produced a 486SX chip which was identical to the DX except that the   
   numeric coprocessor was disabled! Machines sold with this chip had an   
   empty socket where you could plug in a 486DX chip to get a coproc. So   
   once you did that, you could unplug the SX chip and use it elsewhere,   
   right? WRONG!!! It was set up so that the DX in those machines   
   wouldn't work unless the SX was plugged in, doing nothing.   
      
   --   
   Tim Slattery   
   timslattery  utexas  edu   
      
   --- SoupGate-Win32 v1.05   
    * Origin: you cannot sedate... all the things you hate (1:229/2)