Assembly Language Program to SUBTRACT two 8-bit numbers 8086

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data segment

no1 db 02h

no2 db 03h

ans db ?

data ends

code segment

start : assume  cs :code,  ds :data

mov ax ,data

mov ds , ax

mov al , no1

mov bl ,no2

SUB al, b1

mov ans ,al

mov ah ,4ch

int 21h

code ends

end start

In assembly language 8086 we use mnemonics in order to perform arithmetic operations like SUB/SBB in subtraction.
So, Let's dive deep into what  SUB and SBB is ...

SUB:- It subtracts the data in source from data in destination and then stores result in destination. Source can be memory location or register or a number but destination should be register or a memory location(not immediate number). Remember that source and destination should be of same type and both shouldn't be memory locations.

Syntax: SUB <destination> <source>
Operation: destination← destination - source

SBB:- It is used to subtract source-operand and borrow. from destination-operand and then the result is stored in destination. Source can be memory location or register or a number but destination should be register or a memory location(not immediate number). Remember that source and destination should be of same type and both shouldn't be memory locations.

Syntax: SBB <destination> <source>
Operation: destination← destination - source - carry flag

Which flags get affected?
Ans- OF , CF, PF , AF, SF , ZF .

Addition of 8-bit  BCD8086 program

addition of 16-bit bcd program

Division of 32/16 bit program

Subtraction of 8-bit program

Subtraction of 8-bit BCD program

Subtraction of 16-bit program

Subtraction of 16-bit BCD program

Programs:-


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