[geeks] Sun CMOS PROM again..

[Jochen Kunz]

On Wed, 12 Dec 2012 16:49:54 -0500
Jonathan Katz <jon at jonworld.com> wrote:

> I'm still hacking away on this, quite literally. The issue is I'm
> dealing with an Ultra 2 Prom, a 525-1417 ... it has 14 pins on each
> side, not 12, so I'm not sure which pin is Ground.
Well. Then pin 14 may be GND. Have a look in the data sheet of the chip
or meter the resistance from the pins of the chip socket to the GND pin
of the PSU... It should not be hard to identify the GND pin of the chip.

> There is no obvious
> "epoxy" on the side as with older-style chips, either. I'm working
> away on the side with a Dremel trying to find the two find the two
> leads to tie into. Is there something different for this chip?
Maybe. Usually I work down from the top-right. I.e. I start to file
down the top on the right side of the part until I get to the battery.

If you look from the side:
          file
           ||
           \/
+--------+ 
|        +---+
|XTAL     BAT|
++++++++++++++
||||||||||||||  <= pins
1               <= pin 1 to the left
-- 


\end{Jochen}

\ref{http://www.unixag-kl.fh-kl.de/~jkunz/}