re-program 8253 PIT

Can think of 2 things: (I assume a PC) a) write a small TSR that listens to the interrupt, captures 18 of them, and let the 19th pass (you need to shorten the interval somewhat) b) since the longest interval one timer can do is about 55 ms, (in a PC!) you need to use 2 -- load one with a number >= 19, and when the other counter counts down to 0 decrement that number, and when it's down to 0, generate an interrupt.

a) is definitely doable, but I'm not sure about b)

approx.