[vcf-midatlantic] Dallas TOD replacement (was: Feb 2017 workshop)

[Herb Johnson]

 >> "J. Alexander Jacocks  writes:
 >>
 >>> Alex J. worked on the Commodore PC-III, and the Emerson 286, from
 >>> the storage area.  Both need batteries, and I took the Emerson
 >>> with me, for modding of the Dallas chip.

There is a literal "mod" of Dallas chips:

http://www.retrotechnology.com/herbs_stuff/sgi_battery.html

wherein you slice into the epoxy package and splice in a watch battery. 
if this is the mod you are doing, I'd be glad to reference any Web page 
you have about doing it.

There are likely some old versions of the Dallas time-of-day chip and 
RAM which have no modern version. That said:

VAXman posted:

> The DS1287A was fairly common TOY clock back then.  You can replace it with
> the newer DS12887A.  Goggle it, there are ample sources.

...one has to replace it with a compatible device, and it's a bit of 
work and luck to determine if any replacement is likely to work. 
Whereas, you have the chip-in-hand, that only has a dead battery.

Herb

-- 
Herbert R. Johnson, New Jersey in the USA
http://www.retrotechnology.com OR .net