Re: A86: Re: LCD stuff


[Prev][Next][Index][Thread]

Re: A86: Re: LCD stuff




>> 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?
> 
> This was documented on ticalc.org when it first opened.  It's
> probably still there, hidden in some directory.  The TI-85
> consumes 8 microamps or something like that when off.
> It will theoretically drain your AAA batteries in 350 years.

As I remember, Magnus Hagander tested the power consumption
of the TI-85 in several different states to refute the argument that
Z-Shell uses more power than the operating system.  This was
way back in the old days.