;MONOFF.8 - TSR which hooks interrupt 1Bh (CTRL-Break response)
;           And toggles the monitor ON/STANDBY
;(c) 1996 - Sam Hawker - E-mail: shawkie@geocities.com

MAIN:   MOV AX,251Bh      ;Function 25h: Set interrupt vector 1Bh
        MOV DX,NEWINT     ;Offset of handler                                   
        INT 21h           ;Int 21h: Function 25h
        MOV DX,16h        ;Set 16h paragraphs to stay resident
        MOV AH,31h        ;Function 31h: Terminate and stay resident
        INT 21h           ;Int 21h: Function 31h

NEWINT: PUSHA             ;Save registers
        MOV AX,4F10h
        MOV BL,02h
        INT 10h           ;Get current power status
        CMP AL,4Fh
        JNE QUIT          ;Not supported
        MOV AX,4F10h
        MOV BL,01h
        INC BH
        CMP BH,01h
        JE  SET           ;Set to STANDBY
        MOV BH,00h        ;Set to ON
SET:    INT 10h           ;Set power status
QUIT:   POPA              ;Restore registers
        IRET              ;Return from interrupt handler