Xseg at 20
buf: ds 2
Cseg at 0

mov DPTR, #40H; ;buffer

sjmp sign_check

input:
sign_check:
    mov a, P1
    anl a, #0xf0 //(xA>>4)
    swap a //(xA>>4)
    subb a, #0x0f // x-13

    jnz positive
    mov r3, #1 ;flag of negative

positive:
    mov a, P1  ;minor half byte of P0
    anl a, #0x0f
    mov b, #100
    mul ab
    mov r6, a
    ;;movx @DPTR, a

    mov a, P0 ;major half byte of P1
    swap a
    anl a, #0x0f
    mov b, #10
    mul ab
    mov b, r6
    add a, b
    mov r6, a

    mov a, P0 ;minor half byte of P1
    anl a, #0x0f
    mov b, r6
    add a, b
    mov r6, a

test_sign:
    mov a, r3
    subb a, #1
    jnz to_memory

    mov a, #0xff ;inverse to additional code
    subb a, r6
    inc a

to_memory:
    movx @dptr, a
 

output:
    mov r3, #0
    mov a, #0
    movx a, @dptr
    mov  r6, a
    jnb ACC.7, positive_out

negative_out:
    mov a, #0xFF ;inverse number to output
    subb a, r6
    inc a
    mov r6, a
    mov r3, #1



positive_out:
    mov a, r6
    mov b, #10
    div ab
    mov r5, b

    mov b, #10
    div ab
    mov r4, a
    mov a, b
    swap a
    orl a, r5

    mov P2, a

    mov a, r4
    mov b, #10
    div ab

    clr a
    add a, r3
    jz final
    mov a, #0xf0

final:
    orl a, b
    mov P3, a

    jmp $
end