symbiface 2 real time clock

[arnoldemu]

Hi, if you have a symbiface 2 please post the information on top of the RTC chip. It's the tall rectangular one on it with DS or Dallas written on it. I am interested to know which versions were used in the Symbiface 2 production.

Mine has a DS12887A.
The picture on the SymbOS website shows a DS1287A.

What does yours show?

Also it appears the battery in mine has failed, the chip doesn't seem to be responding at the moment. All registers seem to be returning ff.
Or is there another power supply or link I need to connect to make it work? Or do I need to replace the CR2032 (or is that to protect the rom contents that are stored in the static ram)?

[TotO]

The DS12887A is identical in form, fit, and function to the DS1287A, and includes additional 64 bytes of general-purpose RAM.

[gerald]

DS12887/DS1287 have internal battery, you need to replace the whole device when it's empty.

[dxs]

Check this out:


Reworking the DS1287 / DS1387 RTC chip

[arnoldemu]

The DS12887A is identical in form, fit, and function to the DS1287A, and includes additional 64 bytes of general-purpose RAM.

Yes I wondered if other models were used in the symbiface 2 - more for emulation purposes

[arnoldemu]

Check this out:


Reworking the DS1287 / DS1387 RTC chip

I may have a go at this....

[TotO]

Yes I wondered if other models were used in the symbiface 2 - more for emulation purposes

Sorry. I don't know.

[slarti]

Hello arnoldemu

you may ask Dr. Zed for that - he might knew which parts he used for the SF2.

I hope this helps.

[Bryce]

Check this out:

Reworking the DS1287 / DS1387 RTC chip

I've done this "operation" for several people in the past (not for SF2 though).

Bryce.

[TotO]

Here some Dallas chip in stock: DALLAS DS12887 - buyICnow.com
Good price, serious seller, but not new so the battery life is unknown.

[Bryce]

Here some Dallas chip in stock: DALLAS DS12887 - buyICnow.com
Good price, serious seller, but not new so the battery life is unknown.

Well they could be bought and converted (External battery) for people to replace the one on their SFII?

Bryce.

[TotO]

They can be used first without modifications.
The battery should work an undefined time (days, months, years) before requiring any hack.

[dxs]

When I bought the Dallas modules for the RTC MX4 card I made, I first intended to run them on internal battery as they were New Old Stock.
However it turned out that out of 25 only a handful showed battery voltage above 2.5v (there is a 3v  lithium cell inside). Timekeeping accuracy what unacceptable for most of them.
Hence I would rather advise to check batt voltage before bothering to solder anything, even if NOS.

[Bryce]

They can be used first without modifications.
The battery should work an undefined time (days, months, years) before requiring any hack.

Even if they haven't ever been used in a device, the battery is still connected and discharges at the same rate, so it will be as empty as the one used on the SFII.

Bryce.

Gesendet von meinem Motorola DynaTEC 8000X mit Tapatalk 2.

[TFM]

From my experience I can tell that some RTCs work 10 years longer than others of the same batch. There is no general rule, nothing you can rely on. It depends on moon shine and so on. 

[TFM]

BTW: If somebody wants a cool working RTC with ever living battery now, please look here:


Real Time Clock Board

[TotO]

The DS12887 Real Time Clock plus RAM is designed to be a direct replacement for the DS1287.
But, sadly they have not made it battery independent and no new versions are produced today...

[TFM]

Hmmm... that just cries for a hack!