Project2.exe_.~asm

.MODEL small
.STACK 256
.DATA
;Ahmad Hammad 1081443
welcome db 'Ahmad Hammad : 1081443 - project #2',10,13,'$'
line db '-------------------------------------',10,13,'$'
filename db 'input.txt',0
filenameresult db 'output.txt',0

handle dw 0   ; will be the file handle. the number that DOS assigns to the open file.
buffer db 255 DUP ('$')   ; make a plain buffer (not a strange input one like before).

NLine db 13,10,'$'
len dw 0
len2 db 255   ; we need an input buffer this time.



act db 0
.CODE
MOV AX,@DATA
MOV DS,AX



mov ah,09h
lea dx,welcome
mov dx, offset welcome
int 21h

mov ah,09h
lea dx,line
mov dx, offset line
int 21h


mov ah,3Dh   ; 3Dh of DOS Services opens a file.
mov al,0   ; 0 - for reading. 1 - for writing. 2 - both
mov dx,offset filename  ; make a pointer to the filename
int 21h   ; call DOS
mov handle,ax   ; Function 3Dh returns the file handle in AX, here we save it for later use.

;'DOS Service Function number 3Fh reads from a file.

mov ah,3Fh
mov cx,27   ; I will assume ELMO.TXT has atleast 4 bytes in it. CX is how many bytes to read.
mov dx,offset buffer  ; DOS Functions like DX having pointers for some reason.
mov bx,handle    ; BX needs the file handle.
int 21h   ; call DOS

;Here we will put a $ after 4 bytes in the buffer and print the data read:

mov dx,offset buffer
add dx,ax    ; Function 3Fh returns the actual amount of bytes read in AX (should be 4 if
; nothing went wrong.
mov bx,dx
mov byte [bx],'$'   ; byte pointer so we don't mess with the whole word (a word is 16bits).

mov cl,20
mov bl,1
mov dx,offset buffer    ; put the pointer back in DX.
mov ah,9
int 21h    ; call DOS Function 9 (Print String).
mov dx,offset NLine   ; put the pointer back in DX.
mov ah,9
int 21h    ; call DOS Function 9 (Print String).


call to_lower
return:
; call Print
lea si,buffer


mov dx,offset buffer    ; put the pointer back in DX.
mov ah,9
int 21h    ; call DOS Function 9 (Print String).
mov dx,offset NLine   ; put the pointer back in DX.
mov ah,9
int 21h    ; call DOS Function 9 (Print String).
;;;;;;;;;;;;;;;;;;;;;;;;++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
label:
mov al,[si]
;mov dl,al
;mov ah,2h
; int 21h
call moving1
cmp al,'a'
jge changeLetter
;    cmp al,'A'
; jge changeLetter1step
inc si
dec cl


; mov bl,0
jnz label
;;;;;;;;;;;;;;;;;;;;;;;;++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
jz Print
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
changeLetter:

cmp bl,1
je changefirst
inc si

dec cl

jnz label
;;;;;;;;;;;;;;;;
jz Print; dont go down

jnz label
changefirst:
;inc si

mov al,[si]
sub al,32d
mov [si],al
mov bl,0

inc si
; dec cl
jnz label
;ret
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;




moving1:
cmp al,' '
je increment
cmp al,'Z'
jle decrement
ret
increment:
mov bl,1
ret

decrement:
mov bl,0
ret





to_lower:
lea si,buffer

lower:
mov al,[si]
cmp al,60h
jg inc_di_lo
cmp al,40h
jl inc_di_lo
add al,20h
mov [si],al
inc si
jmp lower
inc_di_lo:
inc si
cmp al,'$'
je return
jmp lower



Print:

mov dx,offset buffer  ; put the pointer back in DX.
mov ah,9
int 21h    ; call DOS Function 9 (Print String).



;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
mov dx,offset filenameresult ; put offset of filename in dx
mov cx,0 ; clear cx - make ordinary file
mov ah,3Ch ; function 3Ch - create a file
int 21h ; call DOS service
;mov dx,offset  ; put offset of filename in dx
mov ah,3Dh   ; 3Dh of DOS Services opens a file.
mov al,1   ; 0 - for reading. 1 - for writing. 2 - both
mov dx,offset filenameresult  ; make a pointer to the filename
int 21h   ; call DOS
mov handle,ax   ; Function 3Dh returns the file handle in AX, here we save it for later use.

;Get input:

;    mov ah,0Ah
;mov dx,offset buffer
;int 21h

;    DOS Service Function number 40h writes to a file.

mov ah,40h
mov bx,255 ; pointer to number of bytes read from user.
mov cl,27  ; get the contents of the byte at the pointer.
; note that even though CX takes the length, CL physically IS the low byte of CX.
mov dx,offset buffer  ; pointer to the actual data in DX.
mov bx,handle    ; BX needs the file handle.
int 21h   ; call DOS
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
mov ah,4Ch
int 21h      ; Function 4Ch (Exit Program)

end



; [SOURCE]: C:\emu8086\MyBuild\Project2.asm