Attention! - we only deal with hardware interrupts! TVicHW32 does not support DOS/BIOS functions call. It is assumed that a user is well familiar with hardware interrupts and has some relevant experience.
The UnmaskInterrupt method unmasks specified Irq number at hardware level. So, if the OnHwInterrupt even handler has been installed it called every time when the hardware interrupt occurs.
It works as follows:
var
IrqCounter : Longword;
// The interrupt handler
procedure TIrqForm.OnHwInterrupt(IrqNumber: Word);
begin
Inc(IrqCounter); // increase interrupt counter
end;
...
// Main program
HW32.OpenDriver
if HW32.ActiveHW then
begin
HW32.UnmaskInterrupt(7); // unmask Irq7 (LPT)
end
else ... // failed
Calling the MaskInterrupt stops hardware interrupt processing: