Re: A89: Re: 89 timer


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Re: A89: Re: 89 timer




Really?  I wrote a clock for the TI-86 (calc had to stay on), but I came to
the conclusion that it wouldn't work for two reasons:

1) The interrupt speed is variable, depending on the batteries.  On the
Z80-based TI-86 (and 85), they should occur exactly 200 times a second.
However, I  ended up using something like 175 times a second in my program.
 Is this the same on the 89/92, or is it constant?

2) When the calculator is off, it turns off the LCD and executes a HALT to
wait in low power mode for the ON interrupt.  You'd have to simulate the
calc being off by shutting off the screen, wait for the interrupt (timer),
update your clock counter and HALT again until the next one.  This occuring
175-200 times a second would use up much more power than when normally off.

But if it was possible, there could be several uses.  This would be a nice
feature to add to the FlashROM...

At 09:58 PM 9/8/98 -0600, you wrote:
>
>That can easily be done.  In fact, I programmed a little clock for the ti-85
>that would work even when you turned the calc off (using an int).  It's all
>just a matter of waiting until we have better access to ASM on the 89.
>
>-----Original Message-----
>From: Mrosst92@aol.com <Mrosst92@aol.com>
>To: assembly-89@lists.ticalc.org <assembly-89@lists.ticalc.org>
>Date: Tuesday, September 08, 1998 2:49 PM
>Subject: A89: 89 timer
>
>
>>
>>I would like to know if there is any programmer I could commission to make
>a
>>small ASM program to act as a timer.   I don't need it for months but I was
>>just wondering if someone would make it.  I know ASM is not available yet
>but
>>I have time.  The timer would need to pause the calculator for a variable
>time
>>from 0 to 1 sec. accuracy +- 0.0025 sec., or better.  I would attempt to
>make
>>it my self but I use a Mac and there arn't normally any ASM stuff for Mac
>so I
>>didn't learn much.
>>
>>Matt Ross
>

--
David Phillips
mailto:electrum@tfs.net
ICQ: 13811951
AOL/AIM: Electrum32


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