Rotate Field Dispatching Jump Table

This idiomatic macro usage generates a jump table with eight entries, one each for the eight possible codes in the rotate field of the operate instruction.
 
 GP1.6    NULL
          ECHO   1,OPR=(INT1,BSW,RAL,RTL,RAR,RTR,ERR,ERR) 
+         EQ     OPR
 
 EQ is the CDC-6000's unconditinal jump instruction. The plus sign (+) insures that the jump is the first instruction of a new word, a placement called forced upper.
 

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