code_seg segment
assume cs:code_seg, ds:code_seg,ss:code_seg
org 100h

;============ macro ====================
EM EQU 13
NL EQU 10
Space EQU 20h

print_letter macro letter
push AX
push DX
mov DL, letter
mov AH, 02
int 21h
pop DX
pop AX
endm

print_mes macro message
local msg, nxt
push AX
push DX
mov DX, offset msg
mov AH, 09h
int 21h
pop DX
pop AX
jmp nxt
msg DB message,'$'
nxt:
endm

;================ start of program ============
;================== read files =================
start:
; read recoder file
mov al, 2 ; open existing file
    mov dx, offset filename
    mov ah, 3dh
    int 21h
    jc error
    mov handle, ax; save descriptor
    jmp cont
error:
    print_mes 'Cannot open Recoder.txt';
    int 20h
cont:
    mov AH,3Fh; read
    mov BX, handle ; descriptor
    mov CX, 52*5; how much to read
    mov DX, offset bufDescr ; read here
    int 21h
    mov CX,AX ; Real readed
;close Recoder.txt
MOV AH, 3Eh ;
MOV BX, handle
INT 21h
;=======================================================
; read file to recode
print_mes 'Input File Name > '
mov AH, 0Ah
mov DX, offset FileName
int 21h
print_letter EM
print_letter NL
;===============================================================
xor BH, BH
mov BL, FileName[1]
mov FileName[BX+2], 0
;===============================================================
mov AX, 3D02h ; Open file for read /write
mov DX, offset FileName+2
int 21h
jnc openOK
print_letter EM
print_letter NL
print_mes 'Cannot open Text.txt'
int 20h
;===============================================================
openOK:
mov handle, ax
print_letter EM
print_letter NL
print_mes 'Text.txt is opened'
mov AH,3Fh; read
mov BX, handle ; descriptor
mov CX, 80; how much to read
mov DX, offset bufFile ; read here
int 21h
mov CX,AX ; Real readed
mov readed1, cx; copy readed
;============= end of reading files ============
mov AX, 3D02h ; Open file for read /write
mov DX, offset FileOutName
int 21h
mov handleOut,  AX;
jnc openOK1
print_letter EM
print_letter NL
print_mes 'Cannot open TextOut.txt'
int 20h
openOK1:
print_letter EM
print_letter NL
  print_mes 'open TextOut.txt'
; change Text.txt
mov BX, offset bufOut
cycle:
    mov SI, offset bufFile
cycle1:
    push CX;
    mov DL, byte ptr [SI]
    mov CX,52*5
    mov DI, offset bufDescr
@:
    mov DH, byte ptr [DI]
    cmp DL, DH
    je change
    inc DI; go to next symbol in Recoder.txt
    inc DI
    inc DI
    inc DI
    inc DI
     loop @
 change:
    inc DI
    inc DI
    ; change symbol
    mov AL, byte ptr [DI]
    mov byte ptr [BX], AL
    inc BX
    inc SI; go to next symbol in file
    pop CX
     loop cycle1
;=================================================
@cont:
MOV AH, 40h ; Write in file function
MOV BX, handleOut ; descriptor
MOV CX, readed1 ; Number of writed bytes
MOV DX, OFFSET bufOut ; Buffer adress
INT 21h
; close files
MOV AH, 3Eh ;
MOV BX, handle
INT 21h
mov AH,3Eh
mov BX, handleOut
int 21h

;================ end of program ==============
print_letter EM
print_letter NL
print_mes 'Program completed'

;output buffers after program
print_letter EM
print_letter NL

print_letter EM
print_letter NL
mov AH, 09h
mov DX, offset bufFile
int 21h
print_letter EM
print_letter NL
mov AH, 09h
mov DX, offset bufout
int 21h

mov AX, 4c00h; exit function
int 21h
;===================== data ====================
bufDescr db 52*5 dup (' '),'$';
bufFile  db 80 dup (' ');
DB '$'
BufLen EQU $ - bufFile
bufout  db 80 dup (' ');
BufLenOut EQU $ - bufOut
DB '$'
readed1 dw ?
FileOut db "TextOut.txt",0
File db 14,0,14 dup (0)
filename db "Recoder.txt", 0
FileOutName DB 'TextOut.txt',0
handleOut dw ?
handle dw ?
code_seg ends
end start