Date   : Wed, 03 Apr 1991 20:45:02 GMT
From   : theory.tn.cornell.edu!gould@THEORY.TN.CORNELL.EDU (EWD)
Subject: Sanyo MBC-1000 Interrupts

Greetings:

I've come up with a use for my Sanyo MBC-1000 that
requires a fairly good idea of the passage of time.

Since it has no clock (or does it?), I was going
to write myself characters at 300 baud with an isr
to update a counter and start over (seemed like
a good kluge at the time.)  But looking at the 
schematic I saw an 8253-5 interval timer just sitting
there doing nothing and was delighted to think I 
could do it right.

So I can load the timer and read the contents, but
I need to keep track of each time it times out 
timer 1, every half hour or so.  It looks like this
can be done by setting it up to generate an interrupt
and incrementing a counter in memory, but I don't
see how all this works by looking at the schematic.

I can do it by polling the timer values in a 
keyboard-idle loop, but would prefer to try the
interrupt route first.

Can anybody give me a rundown on how to go about this?

Thanks,

   Eliot


Eliot W. Dudley                       edudley@rodan.acs.syr.edu
RD 1, Box 66
Cato, New York   13033                315 437 0534