DS12887 pcb substitute with battery

[Chuck Guzis]

On 01/22/2017 01:49 PM, Maciej W. Rozycki wrote:

> A problem with reworking is there is sometimes very little clearance
>  available, so any modification has to be made in a clever way or you
> risk a short-circuit.  For example in DECstation 5000 systems their
> DS1287 chip is located in the TURBOchannel option slot area with the
> top of the chip almost reaching the solder side of the PCB of any
> option plugged in there.

Although there are several illustrations of the DS1287 rework where a
coin-cell holder was placed atop the chip, there's absolutely no reason
why that has to be so.  A couple of wire leads away to an off-board
battery holder, holding, say, an ER14250 half-AA.will work just fine and
keep the battery away from the PCB--or a couple of alkaline AA cells,
which should last a few years.  No reason to stick to lithium.

You know--"use your wetware".

--Chuck