Re: Z-RAM ultra 2... replacing the battery?

[Gary <dontyouspamme_vengefultacos@comcast.nospam.net>]

Hi John,

That sounds like a great solution. One question: I assume that when the
computer is on, there's a voltage across the battery connections that would
recharge a nicad (or whatever type of rechargeable battery the Varta was).
Did you use rechargeables, or straight alkaline batteries for this?

John Van Winkle wrote:

> Gary,
> 
> I had an AE Time II clock card that had a Varta 3.6v 100mah battery.  I
> went to radio shack and bought a new
> battery pack and 2 double AA batteries at 1.2V apiece and soldered it to
> the
> card.  The Time II  keeps great time
> now.  If you would like, I can send you a pic of my card and the battery I
> had and the mod I made.   Just email me at appleiieman@charter.net
> 
> John Van Winkle
> 
> "Gary" <dontyouspamme_vengefultacos@comcast.nospam.net> wrote in message
> news:GAvWc.78060$TI1.15396@attbi_s52...
>> So, after having a fit of nostalgia, I dug my trusty //c out from
>> storage, and tried booting it up. In retrospect, this thing was pretty
>> tricked out for its day... 1MB of RAM in a Z-Ram ultra 2 card (the one
>> with a built-in clock... wow, remember when having a clock in a computer
>> was a big deal?), a 65802, and a 3.5" Unidisk.
>>
>> Anyhow, trying to boot up using my old usual boot disks resulted in the
>> system diving into the monitor after displaying "setting the real time
>> clock" which was what the system program that Applied Engineering
>> supplied to read the clock on the card would print on the screen. It took
>> a while, but I was able to find a boot disk that didn't have the clock
>> system file on it (I had been pretty thorough in putting it on just about
>> any disk I would normally boot). That disk booted up just fine, and
>> removing the clock.system file from the other boot disks had them boot up
>> just fine as well.
>>
>> I'm guessing that the battery backup in this thing must be toast, and
>> that the battery was the only way the clock chip got power, because even
>> warm booting the system still gets the same message. On the plus side,
>> the RAM expansion function of the board seems to be working just fine.
>>
>> I just disassembled the //c and removed the Z-ram board. Fortunately, the
>> battery didn't explode and leak noxious stuff all over the place. The
>> battery is pretty easy to spot on the card... a large black rectangle
>> labeled "VARTA Mempac 3.6V 100mAh 53010 703 012." Looking at the back of
>> the board, I can see that the battery seems to have four pins on it that
>> have been soldered into place. The pins aren't labeled on the back (in
>> fact, there are no traces leading away from the pins on the back... I
> guess
>> they must be on the front.) I'm hoping that the traces are labelled on
>> the front... or perhaps that the bottom of the battery itself is labeled.
>>
>> Before I grab a soldering iron and start messing with this, I thought I'd
>> check to see if anyone else has managed to find a replacement for the
>> battery and successfully completed a transplant. I googled for Varta
>> batteries, and found they are still in business, but as far as I can
>> tell, they no longer manufacture a battery with the same specs and same
>> form factor as the one on the Z-Ram board.
>>
>> So, anyone replace one of these batteries before? Any tips on what to
>> look out for? I would like to at least get the battery off of the board,
>> so
> that
>> there's no chance for a toxic spill should the thing decide to break
>> open. Getting the clock functioning again would be a nice bonus.
>>
>> I was thinking that I would perhaps just desolder the thing, and then run
>> leads outside of the case to an external battery enclosure... that way I
>> could replace the battery without opening up the much-abused //c's case
>> again, and could pull the battery in case I put it back into long-term
>> storage. I assume I can find some sort of replacement battery for this,
>> as long as I match the specs printed on it, right? (voltage and mAh).
>>
>> Thanks,
>> Gary
>>
>>
>>
>>
>>