.model large
code segment
assume cs:code, ds:code, es:code, ss:code
org 100h
start:

 jmp beg

 print_symbol:
  push ax
  push dx
  mov ah, 02h
  mov dl, dh
  cmp dl, 0
  je t2
  int 21h
  t2:
  pop dx
  int 21h
  pop ax
  ret

 print_number:
  push ax
  push bx
  push cx
  push dx
  mov ax, dx
  mov bx, 10
  mov cx, 0
  getdigits:
   mov dx, 0
   div bx
   inc cx
   add dx, 30h
   push dx
   cmp ax, 0
   jnz getdigits
  mov ah, 02h
  printdigits:
   pop dx
   int 21h
   loop printdigits
  pop dx
  pop cx
  pop bx
  pop ax
  ret

 debug:
  cli
  push bp
  mov bp, sp
  push ax
  push bx
  push cx
  push dx
  push si
  mov dx, '['
  call print_symbol
  mov dx, [bp+2]
  call print_number
  mov dx, ','
  call print_symbol
  mov dx, [bp-2]
  call print_number
  mov dx, ']'
  call print_symbol
  mov dx, etr
  call print_symbol
  xor ax, ax
  int 16h
  pop si
  pop dx
  pop cx
  pop bx
  pop ax
  pop bp
  sti
  iret

 thread:
  mov ax, 1
  mov cx, 10
  t1:
   add ax, ax
   loop t1
  ret

 beg:
  mov ax, 3501h
  int 21h
  mov int1, bx
  mov int1+2, es
  push cs
  pop ds
  mov dx, offset debug
  mov ax, 2501h
  int 21h
  pushf
  push offset exit
  pushf
  pop ax
  or ax, 100h
  push ax
  push cs
  push offset thread
  iret

 exit:
  popf
  lea dx, int1
  mov ax, 2501h
  int 21h
  mov ah, 01h
  int 21h
  int 20h

int1 dw 0h, 0h
etr dw 0Ah, 0Dh

code ends
end start