Re: A86: Re: LCD stuff
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Re: A86: Re: LCD stuff
AFAIK if you use this routine and pull the AAA batteries, it will reset
the memory, so it doesn't really turn the calc completely "off".
However, the power usage is still very low in this state... I don't
think it would drain your batteries noticably to leave it this way for a
while. I think you need to use port 4 in some way to actually turn it
off...
Cassady Roop wrote:
>
> By the way, how much power does the processor consume when the calc is
> 'off'? I looked up the halt instruction in the z80 data book to try and
> resolve an old dispute with a friend of mine over whether it is ever
> truly off or not (off as in no power usage). I found that the halt
> instruction waits for an interrupt, during which time it runs a
> continual cycle of NOP instructions internally, to maintain memory
> refresh logic for dynamic memory chips. I don't think the 86 uses
> dynamic memory (or maybe it does?), but the z80 still runs during a
> halt, so therefore it must consume power, so therefore the calculator is
> never truly turned off except when the batteries have been removed. How
> much power does it take? If you left it off for a long time, would your
> batts run down?
>
> Can the processor run off the backup battery, or is the backup battery
> isolated to the memory power circuit?
>
> Cassady Roop
>
> > Is it relying on the back-up or regular batteries when
> > the LCD is off using this method?
> >
> > -Barcode (Andy D.)
--
Aaron Curtis <acurti1@umbc.edu>
http://www.gl.umbc.edu/~acurti1
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