From: ohland@charter.net   
      
   https://patents.google.com/patent/US5276864A/en   
      
   Note that IBM says "certain", not "all"   
      
   I would hazard a guess that the NPU socket should be probulated.   
   Continuing to scan...   
      
   FIG. 5 is a schematic representation of the states of certain control   
   signals exchanged in accordance with the present invention between   
   components on the alternate system controller subsystem and on the   
   planar board of the personal computer of FIGS. 1 through 4.   
      
   --- SoupGate-Win32 v1.05   
    * Origin: you cannot sedate... all the things you hate (1:229/2)