Re: A83: Time on TI-83

To: assembly-83@lists.ticalc.org
Subject: Re: A83: Time on TI-83
From: Olle Hedman <oh@hem.passagen.se>
Date: Wed, 11 Nov 1998 02:43:52 +0100
Delivered-To: assembly-83-outgoing@towerguard.unix.edu.sollentuna.se
References: <004101be0cfd$6c688180$83d2928b@david>
Reply-To: assembly-83@lists.ticalc.org


> 
> Wouldn't a counting loop like that consume ALOT of power?  Remember, the Z80
> only uses little power when executing a HALT.  If you could figure out a way
> to let the timer interrupt get called while the calc was off, you could
> update the clock in that like you would when it was on, just don't print the
> time if it's off.

the difference in batteryconsumption is in the scale of mA when running and uA
when in halt.. that is 1000times.. quite a lot...   And one more _big_ problem
about time..  The oscillator circuit in the Ti83 is Very simple..  it is just a
RC-oscilator if I'm not mistaken.. (that is on Capacitator and one Resistor) and
its frequency (and thus the speed of the z80) varies depending on temperature
and batterypower..  very hard to make a clock very exact..

//Olle

References:

Re: A83: Time on TI-83

From: "David Phillips" <electrum@tfs.net>