org  100h

jmp main

    toSwap1     db 'a'
    toSwap2     db 'b'
    result      dw ?
    numToNeg    dw -9
    string      db  'm', 'a', 'g', 's', 'h', 'i', 'm', 'i', 'm', 'v', 'e', 'n', 'e', 'h', 'e', 'n', 'i', 'm' ,0Dh,0Ah,'$'
    array       db "0000", 0Dh,0Ah, 24h ; line feed   return   and  stop symbol 24h=$ (ASCII).
    num1        dw 0xAC45


main: ;using stdcall convention
jmp next
    push numToNeg
    call _negate@2
    PRINTN " ~ Negate ~ "
    call print_num
    PRINTN
    jmp endn

    next:
    mov al,toSwap1
    call print_al_chr
    mov al,toSwap2
    call print_al_chr
    push offset toSwap2 ;b
    push offset toSwap1 ;a
    call _swap@4
    mov al,toSwap1
    call print_al_chr
    mov al,toSwap2
    call print_al_chr









endn:
mov ah,0
int 16h
ret


; ~ Negate ~
; Input - parameter
; Output - through ax register. (2 byte signed integer)
; Function negates the number by 2 completion method.
_negate@2 proc
    push bp
    mov bp,sp
    mov ax,[bp+4]
    not ax
    inc ax
    mov sp,bp
    pop bp
retn 2
_negate@2 endp


; ~ Swap ~
; Input : (char *a, char *b)
; Output : None
; Functions swaps between the values of the two pointers.
_swap@4 proc

    ;num equ 'b'
     push ax
     push bx
     push bp
     mov bp,sp

     mov bx,[bp+8] ;char *a
     mov al, byte ptr [bx]; 'a'
     mov bx, [bp+10] ;char *b
     mov ah, byte ptr [bx]; 'b'
     mov [bx],al
     mov bx, [bp+8]
     mov [bx],ah

     mov sp,bp
     pop bp
     pop bx
     pop ax


retn 4
_swap@4 endp





include magshimim.inc