Question

Assume an array of unsigned eight bit numbers from MX_ARRAY onwards and length of the array is available at ARRAY_LENGTH. Write 8086 assembly language program with apppropriate comments for displaying the contents of MX_ARRAY in binary format, with one array element per row on screen.

ex: for an array element value 30H, display should be 00111011

Answer 1

DATA SEGMENT
HEX DB MX_ARRAY ;The value in MX_ARRAY is copied to DataBit(DB)
BCD DW 0
CNT DB ARRAY_LENGTH ;The array length is copied to the count (CNT)
DATA ENDS
CODE SEGMENT ;Code segment begins
ASSUME CS:CODE,DS:DATA
START:
MOV AX,DATA ;the data is copied to AX register
MOV DS,AX ;the value from AX is moved to DS
MOV AL,HEX ;the HEX number is copied to AL register
CMP AL,00 ;the value in AL is Compared wit 00.
JZ LAST ;if after comparision the value is zero the it jumps to LAST part of the program

LOOP1: ;Conversion Starts from HEX to binary
MOV AH,00 ; if the value is not zero the 00 is copied to AH
MOV BL,0AH ;And 0AH is copied to BL
DIV BL ;the value in AH is divided by 0AH to get a remainder in the from of single number
MOV DH,00 ;now DH is filled with 00
MOV DL,AH ; AH is copied to DL for output
MOV BL,AL ;AL is copied to BL for output
MOV AL,04 ;Now 04 is copied to AL
MUL CNT ;AL is multiplied with CNT
MOV CL,AL ; Copy AL into RAM[CL]
ROL DX,CL ;Rotates the register left by CL bit
OR BCD,DX ; ORing is done between BCD and DX value
MOV AL,BL ;Now BL is Copied to AL
INC CNT ; CNT is incremented to point to next number in the array
CMP AL,0 ; Now AL is compared to check is it contains any number
JNZ LOOP1 ; if AL contains any value the LOOP1 is repeated until Zero
LAST:INT 3
CODE ENDS ; Code segment Ends
END START ; Start ends
END ; Program Ends