Q: reentrant ISR's

["Roland Lang" <lang@decomsys.com>]

Hi.

I have setup a ISR on the 8254 Timer Hardware Interrupt 0.
I am not using the scheduler. I need to program a detection
mechanism whether the ISR is again called before the last one has 
terminated. I need to do this because of a compatibility to 
another system. But it seems the HW Interrupts are turned off 
while the ISR is running so that this detection doesn't work.

My Question: How can I generate a reentrant ISR using RTL2.2?

Thanks for any help.
Kind regards, Roland.