Obtains the address of the current interrupt-handler routine for the specified machine interrupt.
Call with:
AH = 35H
AL = interrupt number
Returns:
ES:BX = segment:offset of interrupt handler
Note:
Together with Int 21H Function 25H (Set Interrupt Vector), this function is used by well-behaved application programs to modify or inspect the machine interrupt vector table.
Example:
Obtain the address of the current interrupt handler for hardware interrupt level 0 (divide by zero) and save it in the variable oldint0.
oldint0 dd ? ; previous handler address
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mov ah,35h ; function number
mov al,0 ; interrupt level
int 21h ; transfer to MS-DOS
; save old handler address
mov word ptr oldint0,bx
mov word ptr oldint0+2,es
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