RE: LZ: Timer interrupt when LCD is off?
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RE: LZ: Timer interrupt when LCD is off?
The ON key itself is an interrupt, so it "wakes up" the processor. When the
calculator is off, the next code that is executed turns on the LCD and resumes
operation. If you just turned off the LCD, the batteries would be drained
really quickly.
________________
Jeff Tyrrill
http://tyrrill-ticalc.home.ml.org/
http://ti-files.home.ml.org/
-----Original Message-----
From: owner-list-zshell@lists.ticalc.org On Behalf Of Rigor Mortis
Sent: Sunday, July 06, 1997 10:59 PM
To: list-zshell@lists.ticalc.org
Subject: Re: LZ: Timer interrupt when LCD is off?
>From all that talk about how the calc is reset if you take out a battery
and press the on key, it would seem that after the calc is turned off,
the processor doesn't do anything until ON is pressed, which would mean
no interrupts are occuring. I don't remember how it checks for the ON
key when it's off though; if it uses an interrupt to check for the ON
key (when it's off), then it might be possible.
If you just turned the LCD off and didn't turn off the rest of the calc
(maybe just set the contrast to 0), the processor would still be
running, and you could have interrupts going, and have a loop checking
for the ON key interrupt.
Hey, I'd love to be proven wrong. Having a clock that keeps the current
time even when the calc is turned off would be nice (like on the HP48).
-mortis
Ess Andreas wrote:
>
> Is that possible? Would be useful for several things, like real-time clocks,
etc.
>
> Andreas
> ----------------
> E-Mail: ess.andreas@computerhaus.at
> Webpage: http://andi.ganymed.org
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