XPost: comp.os.ms-windows.misc, alt.windows7.general, microsoft.   
   ublic.windowsxp.general   
   From: nospam@needed.invalid   
      
   On 12/30/2023 3:27 PM, J. P. Gilliver wrote:   
   > In message <3fj0pi1he28cfgbul4lbmu4jua526btugq@4ax.com> at Sat, 30 Dec 2023   
   12:10:57, Tim Slattery  writes   
   >> "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.   
   >>   
   > Did anyone ever manage to "crack" the 486SX or the 487 to enable the   
   disabled part, or make it work without the other?   
      
   You will remember that these were simpler times.   
      
   Intel has much better mechanisms "to enforce this or that" today.   
      
      https://www.vogons.org/viewtopic.php?t=68471   
      
   Today we have sharks with lasers on their heads. Back then,   
   all we had was sharks.   
      
      Paul   
      
   --- SoupGate-Win32 v1.05   
    * Origin: you cannot sedate... all the things you hate (1:229/2)