Изучение принципов обработки аппаратных прерываний, страница 2

sseg SEGMENT STACK     

      db 64 dup (?)

sseg ENDS

dseg SEGMENT PARA PUBLIC 'DATA'

adr_int:

      ipsave dw 0h

      cssave dw 0h     

      msg db '*$'

dseg ENDS

cseg SEGMENT

main proc FAR

      ASSUME      cs:cseg, ds:dseg, ss:sseg

start:

; Data segment init

      mov ax, dseg     

      mov ds, ax

      ; Get handler int8 adress

      mov ax,3508h           

      int 21h

      mov ipsave, bx   

      mov ax, es

      mov cssave, ax   

      push ds

      mov dx, offset int_8

      mov ax, seg int_8

      mov ds, ax       

      ; Set our handler

      mov ah, 25h

      mov al, 8h       

      int 21h                

      pop ds

      mov ax,0h                   

      ; Work with klav

      int 16h

      push ds

      mov dx, ipsave

      mov ax, cssave

      mov ds, ax

      mov ah, 25h

      mov al, 8h

      int 21h

      pop ds

      ; Exit

      mov ah,4Ch       

      int 21h

main  ENDP

int_8 proc FAR              

      push ax                

      push bx

      push es

      push ds

      push di

      mov ax, dseg

      mov ds,ax

      ; Color Display

      mov ax,0B800h    

      mov es,ax

      lea bx, msg

      ; Where to output

      mov di,7D0h

m1:

      mov al,[bx]

      cmp al,'$'

      je m_ex

      mov es:[di],al

      inc di

      inc bx

      mov es:[di],word ptr 0F0h

      inc di

      jmp m1

m_ex:

      pop di                      

      pop ds

      pop es

      pop bx

      pop ax

      ; Unset int flag

      mov al,20h       

      out 20h,al

      iret

int_8 ENDP

cseg ENDS

END start