Description of how to make use of IRQ 8 through 15
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The Interrupt Mask Register for IRQ 8-15 is at port A1H.
To enable an IRQ, set the corresponding bit to 0 (zero).

The bits are organized as follows:

Bit 0 = IRQ8
Bit 1 = IRQ9
Bit 2 = IRQ10
Bit 3 = IRQ11
Bit 4 = IRQ12
Bit 5 = IRQ13
Bit 6 = IRQ14
Bit 7 = IRQ15


As an example, to enable IRQ10, just do like this:


  mov dx,0A1h
  in  al,dx
  and al,0FBh              ; Set bit 2 to zero
  out dx,al


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The interrupt vector addresses for IRQ 8-15 are as follows:

IRQ8  = INT 70h
IRQ9  = INT 71h
IRQ10 = INT 72h
IRQ11 = INT 73h
IRQ12 = INT 74h
IRQ13 = INT 75h
IRQ14 = INT 76h
IRQ15 = INT 77h


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At the end of an ISR (Interrupt Service Routine), you have to
signal EOI (End of Interrupt) to two ports, A0h and 20h, like this:


    mov al,20h                     ;End of Interrupt commmand
    out 0A0h,al
    out 020h,al

    iret                           ;Return from ISR



Good Luck!

Mr Digger
.