Zamiana Liter ASM

format MZ
entry text:main
stack stk:256

segment stk use16                    ;stack
        db 256 dup(?)

segment data_16 use16
        example:                      ;data
                db 'TOMek',24h,'$'

        db 0dh,0ah,'$'

segment text use16
main:
        mov     ax,data_16
        mov     ds,ax
        mov     ax,stk
        mov     ss,ax
        mov     sp,256
        mov     si,example

        mov     cl,5    ;Okreslenie ilosci liter
        mov     dh,5Ah
        mov     ch,25   ;25 liter w alfabecie

        jmp     change

savestate: mov byte[ds:si], AL  ;Zapisanie wartosci do pamieci
           inc si
           dec cl
           jnz change
           jmp finish

change: mov AL,byte[ds:si]

        decide:                 ;Rozpoznanie wielkosci litery
        cmp     al,dh
        jle     lower
        dec     ch
        jnz     decide
        jmp     higher

        lower:                 ;Dodanie 20h powodujace zmiane wielkosci
        mov     dh,5Ah
        mov     ch,25
        add     al,20h
        jmp     savestate

        higher:                ;Odjecie 20h
        mov     dh,5Ah
        mov     ch,25
        sub     al,20h
        jmp     savestate


finish:

       mov bx,0
       mov ah,9

       mov dx,example        ;Wyswietlanie
       int 21h

       mov ah,1
       int 21h

       mov ax,4c00h          ;zakonczenie programu
       int 21h
       ret