[comp.sys.handhelds] Stange happening on HP48sx

hp@vlsi.polymtl.ca ( club HP) (04/18/91)

Hi, for a few weeks now i have been wondering aroud with machine
language. I have a few questions for the folks who nows more than me:

    I have made a frequency meter that takes a signal from either the
io port (232) or the led. It counts the time it takes for twenty
oscillations from  the counter at #138h. But i have noticed that when
this counter reache 0 and interrupt?? occurs even tougth i cleared
interrupts! Is there any NMI on the hp? I solved the problem by
disabling the clock so this interrupt doesn't append at each second
but at each hours or so.
    The same thing appends with the ON button. My program stops when
the ON is pressed and resume operations when it is released and that
even when the interruptions are disabled!

I have never seen the address of the IR outpout! I hope thats why
there is no self learning remote control for the 48sx because there it is:

#11a bit 1: This is a receive acknolege bit, it togles on when it
receives an IR signal. You can reset this bit by writing a zero to it.

#11a bit 4: This is a receive bit it togles with the input signal.

#11b : same as #11a exept you can't write to it.

#11c: this open's the IR outpout ON and OFF. WARNING putting the IR on
conssumes much power. (I am not sure of the bit but #0 -> OFF #f ->
on)

#11d: This open's the ir outpout for a few msecs (the same length as
for the normal IR transmission) when you write to it. (#f)

 
    I have also the wire port addresses i should be posting them as
soon as i now all about it.

    If any body has anything about how to put an objet to the stack
with garbage collect and everything post it to me at:

	Robin@Ireq-robot.hydro.qc.ca

					Christian Pronovost.