Re: A83: Time on TI-83
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Re: A83: Time on TI-83
Justin Karneges wrote:
> You can still make a clock under those conditions. The 200 times a second
> interrupt is (so I've heard) not always 200 times a second. It depends on
> battery and temp. Now, since the time it takes to execute a Z80 instruction
> is static (go find a z80 instruction table with the number of nanoseconds
> per instruction listed), you could "figure out" the rate of the interrupt
> based on how many "nop"s or whatever that you were able to execute between
> interrupts. Anyways, I'm sure something could be done. Once you know the
> interrupt rate, you can base everything on that. I know that a program
> called "sysmon" for the TI-86 uses this method to display a battery gauge on
> your screen.
>
> -Justin
The _time_ for every instruction is not fixed. it depends on the system
oscillator, the clockfrequency, and because of this, it will not be a fixed
number of interupts per second.. how many interupts per second will depend on
temeperature and battery power, as I said.. so the clock would need to be
tweeked for every new calc it is installed on and retweeked when the battery
goes down.. and it would also need to be retweeked if the temperature is
changing.. i dont think this is very practical.. and the z80 is still taking
1000 times more batterypower, when runnning, then when in halt..
//Olle
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