IFR Com 120B replacement RTC

[AdrianH]

So as the Dallas RTC the DS1286 has been out of production for some years and there are doubts about the age of so called new ones. I decided as well as getting a two DS1286's to buy two DS1284 chips basically what is in the 1286 and to add my own crystal and battery.

So I did these. One has a CR1220 cell holder and the other with holder has a CR2032 cell fitted.



The top of the chip was roughed up with emery as was the base of the battery holders and epoxy used to hold everything in place.

All I can say is that they work, the smaller CR1220 battery which I guess is the size as fitted normally is only around 40mAH. The CR2032 is typically around 240mAH. Although I doubt capacity is the issue more like shelf life.

But it works in the test set, so at least I have a few options for RTC playing!


Adrian

[popcicle90]

How did you manage to keep your options if you replaced the RTC? Are you able to read the old one (somehow), or do you have the options codes for your unit?

[AdrianH]

It may be possible to remove the RTC and read it therefore you can save the RTC for the future. It is a bit like playing Russian Roulette, for some it works for some it means loosing everything as removing the chip can trigger a total loss.

I used an Eprom programmer to read and program another RTC initially before making one just for the task. No I do not have the pass codes that would mean either a crack of the software or someone has the codes. Either way not something to be discussed on here.

Adrian

[jeryray]

So if you managed to pull the ic, read it, program a newer one. You say it worked for you?

[AdrianH]

No it did not work for me, but lets say I have a work around I have used, I lost all the functions I had and ended up with a very basic test set. So I did a lot of digging reading posts and a lot of reading and programming the RTC chip, I in fact even managed to build a programmer just for the RTC chip.

You have a few options,

• Hope the RTC does not fail.
  Grind down the cover and potting, solder an extra battery onto the chip never letting the volts die.
  Try to remove and read the chip if successful as one has been it means you have a backup, but you need a device that can read the RTC.

There are another two ways one includes understanding the bios in the Com120 B and running commands from that, out of my league I am afraid but there are some on here that can.
or
You get a serial number and set of passcodes from some kind person with another Com120B that had gone through the process before when Wowbagger was helping. Last time he came on the forum under Wowbagger was sept 2018 so not sure what happened to him,but I hope he is OK as he gave a lot of information to the forum.

I am unsure what state your machines are in, if working leave alone would be my first response, as said connect a serial lead and follow some of the posts on the forum and record options and serial number, also keep a record of what software versions you are running. I have helped a Com120A user and a couple of B owners. A 120C would be new to me. If a machine fails post me a pm and deal with me off forum and I can possibly help, but unfortunately you would still need a device programmer, and I treat it as a last resort just to stop a machine getting scrapped when the RTC fails.
I am in the UK so can not offer any sort of local help generally.

Adrian

[jeryray]

I was lucky tonight. I removed the Dallas IC, Installed socket. Did not lose the memory.
When my new Ic's come I will read the chip and try the newly programmed DS1284.

Learned a lot here. Hope it works, I have 4 of my own to do and 4 for my friend.