NVIS 5586A, Learning Material

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Nvis 5586A
Nvis Technologies Pvt. Ltd. 120
Program 14:
To multiply an ASCII string of eight numbers by a single ASCII digit. The result is a
string of unpacked BCD digits.
Address Opcode Mnemonic Comments
0400 BE 00 05 MOV SI,0500
LOAD SI REG. WITH STARTING ADDRESS OF STRING
0403 BF 08 05 MOV DI,0508
LOAD DI REG. WITH THE STARTING ADDRESS OF
RESULT LOCNS.
0406 B2 34 MOV DL,34 LOAD DL WITH THE MULTIPLIER ASCII DIGIT
0408 B9 08 00 MOV CX,0008 LOAD COUNTER REG WITH THE NO. OF BYTES IN THE
STRING
040B C6 05 00 MOV BYTE[DI],00
040E 80 E2 0F AND DL, 0F MS NIBBLE OF MULTIPLIER IS ZEROED
0411 8A 04 MOV AL, [SI] FIRST ASCII NO. OF STRING IN AL.
0413 46 INC SI POINT AT THE NEXT LOCN IN STRING (OF ASCII NOS.)
0414 24 0F AND AL, 0F MS NIBBLE AT MULTIPLIER NO GAPAND IS ALSO
ZEROED.
0416 F6 E2 MUL DL PERFORM THE FN. AX = AL* DL
0418 D4 0A AAM PERFORM THE FN AH=AL/0A, AL=REMAINDER.
041A 02 05 ADD AL,[DI] THE CONTENTS OF AL (REMAINDER OBTAINED BY
PERFORMING THE ABOVE OPERATION)
041C 37 AAA ADDED WITH 00 WHICH ARE IN 1ST DEST.LOCN. THE
CONTENTS OF AL ARE UNPACKED DECIMAL NO. AND
ARE STORED IN 1ST DEST. LOCN (=0508).
041D 88 05 MOV [DI],AL
041F 47 INC DI POINT AT THE NEXT DEST. LOCN.
0420 88 25 MOV [DI],AH CONTENTS OF AH (QUOTIENT GOT IN AAM
OPERATION) ARE MOVED IN NEXT BEST. LOCN (0509).