SAP

*        IBM 704 SAP PROGRAM
*        COMPUTE FACTORIAL OF N USING ITERATIVE LOOP
*
         ORG    100
FACTRL   CLA    ONE         LOAD 1 INTO ACCUMULATOR
         STO    RESULT      RESULT = 1
         CLA    N           LOAD N INTO ACCUMULATOR
         STO    CNTR        INITIALIZE COUNTER = N
LOOP     CLA    RESULT      LOAD CURRENT RESULT
         MPY    CNTR        MULTIPLY BY COUNTER VALUE
         STO    RESULT      STORE NEW RESULT
         CLA    CNTR        LOAD COUNTER
         SUB    ONE         DECREMENT BY 1
         STO    CNTR        STORE DECREMENTED COUNTER
         TZE    DONE        IF COUNTER = 0 THEN DONE
         TRA    LOOP        ELSE CONTINUE LOOP
DONE     HTR    0           HALT WITH RESULT IN MEMORY
*
ONE      DEC    1
N        DEC    5           COMPUTE 5 FACTORIAL = 120
CNTR     BSS    1
RESULT   BSS    1
         END    FACTRL