Subtract Two 8 Bit Numbers Code Assembly Language

Write a Program to Subtract Two 8 Bit Numbers in Assembly Language. Program will load two numbers in two registers and then subtract those numbers from one another . It should then display final result as the output of the program .

Consider that a byte of data is present in the AL register and second byte of data is present in the BL register.

We have to subtract the byte in BL from the byte in AL. Using sub instruction subtract the contents of two registers. Result will be stored in the AL register.

Display the result using display routine.

For example :	AL = 0A H		0A H	(10)₁₀
	BL = 04 H	–	04 H	(4)₁₀
			06H

Algorithm to Subtract Two 8 Bit Numbers

Step 1 : Initialize the data segment.

Step 2 : Get the first number in AL register.

Step 3 : Get the second number in BL register.

Step 4 : Subtract the two numbers.

Step 5 : Display the result.

Step 6 : Stop

to+Subtract+Two+8+Bit+Numbers - Subtract Two 8 Bit Numbers Code Assembly Language

Program to Subtract Two 8 Bit Numbers

.model small  <br/> .data  <br/> a db 0AH                                                              <br/> b db 04H  <br/> .code  <br/>      mov      ax, @data      ; Initialize data section  <br/>      mov      ds, ax  <br/>      mov      al, a          ; Load number1 in al  <br/>      mov      bl, b          ; Load number2 in bl  <br/>      sub      al, bl         ; subtract numbers and result in al  <br/>      mov      ch, 02h        ; Count of digits to be displayed  <br/>      mov      cl, 04h        ; Count to roll by 4 bits  <br/>      mov      bh, al         ; Result in reg bh  <br/> l2:     rol      bh, cl      ; roll bl so that msb comes to lsb   <br/>      mov      dl, bh         ; load dl with data to be displayed  <br/>      and      dl, 0fH        ; get only lsb  <br/>      cmp     dl, 09          ; check if digit is 0-9 or letter A-F  <br/>      jbe      l4  <br/>      add      dl, 07         ; if letter add 37H else only add 30H  <br/> l4:     add      dl, 30H  <br/>      mov      ah, 02         ; Function 2 under INT 21H (Display character)  <br/>      int      21H  <br/>      dec      ch             ; Decrement Count  <br/>      jnz      l2  <br/>      mov      ah, 4cH        ; Terminate Program  <br/>      int      21H  <br/>      end

.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 .

C:\>tasm 8bit-sub.asm

Assembling file: 8bit-sub.asm

Error messages: None

Warning messages: None

Passes: 1

Remaining memory: 438k

C:\>tlink 8bit-sub.obj

Warning: No stack

C:\>8bit-sub

Source projectgeek.com

Subtract Two 8 Bit Numbers Code Assembly Language

Algorithm to Subtract Two 8 Bit Numbers

Program to Subtract Two 8 Bit Numbers

How to Run this Program

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