Subtract Two 8 Bit Numbers Code Assembly Language
For example :
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AL = 0A H
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0A H
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(10)10
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BL = 04 H
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–
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04 H
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(4)10
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06H
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Algorithm to Subtract Two 8 Bit Numbers
Program to Subtract Two 8 Bit Numbers
.model small .data a db 0AH b db 04H .code mov ax, @data ; Initialize data section mov ds, ax mov al, a ; Load number1 in al mov bl, b ; Load number2 in bl sub al, bl ; subtract numbers and result in al mov ch, 02h ; Count of digits to be displayed mov cl, 04h ; Count to roll by 4 bits mov bh, al ; Result in reg bh l2: rol bh, cl ; roll bl so that msb comes to lsb mov dl, bh ; load dl with data to be displayed and dl, 0fH ; get only lsb cmp dl, 09 ; check if digit is 0-9 or letter A-F jbe l4 add dl, 07 ; if letter add 37H else only add 30H l4: add dl, 30H mov ah, 02 ; Function 2 under INT 21H (Display character) int 21H dec ch ; Decrement Count jnz l2 mov ah, 4cH ; Terminate Program int 21H end
How to Run this Program
For Running this program you should have installed Tasm on you computer . If you have not installed Tasm yet please install from Here .