[sdiy] Hardware gurus.. I need your opinion here..

[Ben Bradley]

The vintage computer folks have solved this problem with some models
of those battery-backed chips by hacking into the battery connection
and adding a coin cell, I don't know offhand if this can be done with
the one you have:
https://www.vcfed.org/forum/forum/genres/pcs-and-clones/62778-new-way-to-replace-ailing-dallas-rtc-chips

On Fri, Apr 30, 2021 at 4:10 PM Jean-Pierre Desrochers
<jpdesroc at oricom.ca> wrote:
>
> I have a full functional old 90's Tektronix TDS350 that I use a lot.
>
> I love this Faithfull scope but its Dallas non-volatile Ram DS1630AB-120 has a datecode 9430 (1994, 30th week !)
>
> BUT it still keeps its calibration and data memory settings !!
>
> Imagine.. more than 25 years after !
>
> Well because I don't want to push my luck too far here
> I decided to replace this Dallas RAM for something more reliable
> for the next years to come..
>
>
>
> 2 choices:
>
>
>
> Replace it with a small 28DIP600 pcb hybrid filled with
> a non-volatile RAM controller IC + a 32k x 8 SRAM
> using an external connected 3V lithium battery.
>
>
>
> OR
>
>
>
> Buy a genuine Tektronix Dalals DS1630AB-120 like these ones for sale at $14.99US each.
>
> https://www.qservice.tv/vpasp/shopexd.asp?id=12458&bc=no
>
>
> The seller quotes:
>
> ".. the date codes are 9510 or -1995, 10th week"
>
> ".. all these are genuine parts bought from the tektronix surplus store in Beaverton, "
>
>
>
> Here I was aware of the inner battery life span left from the manufacturer's datecode.
> But the actual DS1630AB specs page 10  says:
>
> 9 - Each DS1630 has a built-in switch that disconnects the lithium source until Vcc is first applied by the user.
> The expected Tdr is defined as accumulative time in the absence of Vcc starting from the time power
> is first applied by the user.
>
>
>
> Sure these could have been connected at least once then the battery
> countdown started OR these have never been used..
>
>
>
> What do you think ?
>
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