[OpenIndiana-discuss] Offtopic question to old SPARC users

[Hans J. Albertsson]

I think I got it mixed up; There actually was an earlier similar-purpose 
PROM that could have it's battery health "measured" by shorting some 
pins, and gradually lowering the external Vcc.

You measured the voltage at some other pin and the change in that 
voltage started lagging behind the change in Vcc at a voltage that was 
related to the battery voltage. In those days, that PROM was a rather 
expensive part. That was probably so long ago it might have been an 
Ericsson support computer for remote-location phone station service 
calls rather than a Sun box, and it might have been a war story from 
before my employment at Ericsson.

I think NOT providing a way to measure the battery health in situ was a 
bad design decision.


On 2013-12-23 20:55, David Brodbeck wrote:
> On Sun, Nov 24, 2013 at 9:34 AM, Hans J. Albertsson <
> hans.j.albertsson at branneriet.se> wrote:
>
>> I can't remember any more, but there might be a way to measure the actual
>> in-circuit battery voltage on external pins.
>
> Don't think so, but I did once grind away the chip case to uncover the
> battery connections, and supply external power that way.  Those are some
> memories.  Not often you get to attack a computer with a Dremel. ;)
>
>