AB16-12T3

* NAME: AB16-12T3 DOC 70181010000 REV F PAGE 25

1095 02351 000201 IAB HI-ORDER TO A, LOW ORDER TO B 1096 02352 141216 ACA 1097 02353 0 12 02317 IRS MPY INCREMENT FOR RETURN 1098 02354 0 01 02420 MPCC JMP MEXT EXIT 1099 * 1100 * MULTIPLICATION SUBROUTINE FOR POSITIVE VALUES 1101 * 1102 02355 0 000000 MPYS DAC ** ENTRANCE 1103 02356 0 04 00535 STA COMM STORE MULTIPLICAND 1104 02357 000201 IAB MULTIPLIER IN A MULTIPLICAND IN B. 1105 02360 0 04 00536 STA COMM+1 STORE MULTIPLIER 1106 02361 0 05 00535 ERA COMM IF NEG. MINUS LARGEST NEGATIVE NUMBER 1107 02362 100400 SPL IF ZERO NORMAL OR BOTH ARE LARGEST NEG NO. 1108 02363 0 01 02412 JMP MLNN LARGEST NEG NO. IS PRESENT, MULT. IN B 1109 02364 000201 IAB TEST MULTIPLICAND FOR LNN, IF NEG 1110 02365 101400 SMI BOTH OPERANDS ARE LNN OK FOR BOTH 1.00000. 1111 02366 0 01 02370 JMP *+2 1112 02367 0 01 02406 JMP MPYN RESULT WILL BE ZERO LNN*LNN 1113 * IN A 1114 02370 0 02 00536 LDA COMM+1 NORMAL, MULTIPLY OPERANDS LOAD MULTIPLIER 1115 02371 000201 IAB MULTIPLIER IN B 1116 02372 0 02 00645 MPYR LDA =-15 LOAD COUNTER 1117 02373 0 04 00536 STA COMM+1 LOOP COUNTER 1118 02374 140040 CRA CLEAR A REGISTER 1119 02375 0400 77 LRL 1 SHIFT TO RIGHT 1120 02376 100001 SRC EXAMINE RIGHT MOST BIT 1121 02377 0 06 00535 ADD COMM ADD MULTIPLICAND 1122 02400 0 12 00536 IRS COMM+1 CONTROL LOOP 1123 02401 0 01 02375 JMP *-4 RECYCLE 1124 02402 0400 77 LRL 1 1125 02403 0414 77 LGL 1 PUT 0 IN SIGN ORDER OF A REGISTER 1126 02404 0400 77 LRL 1 MOVE 0 TO SIGN OF B REGISTER 1127 02405 -0 01 02355 JMP* MPYS 1128 02406 140040 MPYN CRA RETURN ZERO RESULT 1129 02407 000201 IAB ZERO IN B 1130 02410 0 02 00535 LDA COMM -1 IN A 1131 02411 0 01 02331 JMP MPYA+1 RESULT CANNOT BE REPRESENTED ABORT WITH -1 1132 * 1133 * MULTIPLY BY LARGEST NEGATIVE NUMBER 1134 * IF RESULT IS NEGATIVE AND THE 1135 * 1. MULTIPLICAND IS LNN, RESULT IS THE TWO'S 1136 * COMPLEMENT OF THE MULTIPLIER 1137 * 2. MULTIPLIER IS LNN, RESULT IS THE TWO'S 1138 * COMPLEMENT OF THE MULTIPLICAND 1139 * IF RESULT IS POSITIVE AND THE 1140 * 1. MULTIPLICAND IS LNN, RESULT IS THE 1141 * MULTIPLIER 1142 * 2. MULTIPLIER IS LNN, RESULT IS THE MULTIPLICAND 1143 * 1144 02412 140040 MLNN CRA CLEAR B