Question

Write an Assembly Language Program to add two BCD number stored at location 2500H and 2501H. Place the BCD result in location 2502H and onward starting with LSB.

Answer 1

        LDA 2500H        ; A = 1st BCD number
        MOV B, A

        LDA 2501H        ; A = 2nd BCD number
        ADD B            ; A = binary sum
        DAA              ; Adjust result to BCD

        STA 2502H        ; Store LSB (BCD result)

        MVI A, 00H       ; Prepare to store carry
        ADC A            ; A = 01H if CY = 1 else 00H
        STA 2503H        ; Store carry as next digit

        HLT