IBM 6644 User Manual

Parts/Test Point Locations  105

NOTE: The whitened pin of a jumper represents 

pin 1. 

System Board Jumper Settings

JP11, JP4 - Reserved
   1-3, 2-4  
   3-5, 4-6

AMP Select:--Reserved
  

JP7 Boot Block CMOS 
Clear
   1-2
   2-3

Clear function

 *Default
 Clear CMOS/Boot Block 
 Recovery