DS1287 realtime clock replacement

[ppppenguin]

I have some kit (not a PC or other computer) that uses a DS1287 realtime clock. Inevitably the battery is dead. Looking online htere are various solutions, including grinding off part of the package to fit an external battery. The simplest solution seems to be this:

https://myretrostore.co.uk/product/ds1287/

Does anyone have any experience of this or other solutions?

[Exiled Yorkshireman]

I've seen various videos of people going down the grinding route. I think I'd prefer the myretrostore solution. I used to like the Dallas battery-backed modules. Indeed, I had a couple of Dallas battery-backed static rams on my sideways ROM module in a BBC model B. As time has passed I've realised they are a ticking time bomb, especially for some vintage test and measurement kit.

[Mike Watterson]

It's easy to break off part of case and put a CR2032 holder. There are photos somewhere. I've done a few.

[DrStrangelove]

Chisel the top off.

Couple of careful saw cuts.

Chisel again.

Two AAA battery holder, 2 bits of wire, solder.

Worked for me several times.

But then again I'm a bodger par excellence.

Then again I wrote off a Compaq Portable III with a similar bodge when the cells leaked.

[ppppenguin]

I've designed those Dallas chips into projects I've done for my clients so I'm as guilty as anyone else. At the time they were seen as a simple and convenient solution. At least with an RTC you aren't losing calibration data as you might in some (for example) Tektronix kit which used similar devices with memory.

I don't have the headroom above the PCB to do very much with cutting it open and fitting an external battery. At least it's plugged into a socket so if I want to bodge it I can do it safely away from the equipment.

[DrStrangelove]

I did the chiselling and sawing in a bench vice.

[pamphonica]

I've done a number of Dallas chips in older testgear using the sawcut technique with a new coin holder above. All worked perfectly. Remember that the key cut is the one that severs the connection from the existing potted coin-cell!
There was also an american company that did a neat pcb to fit above the dallas chip which looks a lot better. Look for "glitch works".

[ppppenguin]

I now have one of those DS1287 replacements https://myretrostore.co.uk/product/ds1287/ and it works. I wasn't impressed by the packaging - expanded polystyrene and bubblewrap. Really should have been antistatic.

I thought I had a suitable CR1220 or CR1225 battery but I was wrong. Available locally at stupid prices so I've ordered from the Small Battery Company https://www.smallbattery.company.org.uk ... ers,CR1225 I've used them many times before.

I may open up the old DS1287 just to have a look.

[pamphonica]

I may open up the old DS1287 just to have a look.

Don't mangle it - it can be resuscitated and re-used!
Jeremy

[Mike Watterson]

Here is inside (from an Atari forum).
   
You can melt case or dremmel to connect one side of new holder and on the other left end you need to cut the wire to the top of the old battery.

Also was sold as ODIN.
I did two hacksaw cuts at the two missing pins and chipped with a small screwdriver. Mine was an ODIN on a 486 PC.


Connections

Code:

________
MOT  1 -|°       |- 24 VCC
X1  2 -|        |- 23 SQW
X2  3 -|        |- 22 N.C.
AD0  4 -|        |- 21 RCLR
AD1  5 -|        |- 20 VBAT
AD2  6 -|  DS12  |- 19 IRQ
AD3  7 -|  887A  |- 18 RES
AD4  8 -|        |- 17 DS
AD5  9 -|        |- 16 GND
AD6 10 -|        |- 15 RW
AD7 11 -|        |- 14 AS
GND 12 -|________|- 13 CS