Why not just buy a brand new DS12887+ from digikey?

maxtherabbit wrote on 2020-03-22, 02:06:

Why not just buy a brand new DS12887+ from digikey?

Good question ! I was stumped by this:

Which chip does the DS1287A use, or is the chip used in the DS1287A actually the DS1287A?

Actually it's not such a silly question, the DS1287 is basically just a DS1285 with built-in battery. So a DS1285 (or better: DS12885, for Y2K support) could be the basis for your own battery mod.

dionb wrote on 2020-03-22, 13:05:

Actually it's not such a silly question, the DS1287 is basically just a DS1285 with built-in battery. So a DS1285 (or better: DS12885, for Y2K support) could be the basis for your own battery mod.

yeah but if you already have the chip removed from the motherboard why screw around with a battery mod? Just grab a brand new module and enjoy the next 25 years of reliable, maintenance free RTC performance

maxtherabbit wrote on 2020-03-22, 02:06:

Why not just buy a brand new DS12887+ from digikey?

Anybody knows the difference between
DS12887A+
and
DS12887+
?

CoffeeOne wrote on 2020-03-22, 14:43:

Anybody knows the difference between DS12887A+ and DS12887+ ? […]
Show full quote

maxtherabbit wrote on 2020-03-22, 02:06:

Why not just buy a brand new DS12887+ from digikey?

Anybody knows the difference between
DS12887A+
and
DS12887+
?

the difference is the presence of the RCLR pin. The A part can be used anywhere that the non-A can

since you have an A part already, grab an A from digikey

https://www.digikey.com/product-detail/en/max … 2887A-ND/956873

maxtherabbit wrote on 2020-03-22, 14:31:

[...]
yeah but if you already have the chip removed from the motherboard why screw around with a battery mod? Just grab a brand new module and enjoy the next 25 years of reliable, maintenance free RTC performance

Money? Delivery? Challenge?

I for one ordered a new Maxim DS12887 last night, but that's because I needed to do an electronics shop anyway, my pay came in and I have a big enough backlog of other challenges. If I'd been strapped for cash and not ordering other stuff anyway, the EUR 11 + EUR 7 for delivery would possibly be prohibitive. With a Dremel, a soldering iron and a coin cell I probably already have, I could fix it up for free. So I can more than understand that someone would want to screw around with one.

maxtherabbit wrote on 2020-03-22, 15:00:

the difference is the presence of the RCLR pin. The A part can be used anywhere that the non-A can
since you have an A part already, grab an A from digikey
https://www.digikey.com/product-detail/en/max … 2887A-ND/956873

I don't have an A part already, I was only interested.
😁

dionb wrote on 2020-03-22, 15:40:

maxtherabbit wrote on 2020-03-22, 14:31:

[...]
yeah but if you already have the chip removed from the motherboard why screw around with a battery mod? Just grab a brand new module and enjoy the next 25 years of reliable, maintenance free RTC performance

Money? Delivery? Challenge?

I for one ordered a new Maxim DS12887 last night, but that's because I needed to do an electronics shop anyway, my pay came in and I have a big enough backlog of other challenges. If I'd been strapped for cash and not ordering other stuff anyway, the EUR 11 + EUR 7 for delivery would possibly be prohibitive. With a Dremel, a soldering iron and a coin cell I probably already have, I could fix it up for free. So I can more than understand that someone would want to screw around with one.

Doesn't everyone place a monthly electronics shop order? I would gladly pay 10 to not end up with a bodged up pile of trash

The reason for doing this is for two reasons. The first is it'll be fun and the second is the battery will be the only thing that ever needs to be replaced.

I've ordered a CR2042 button battery holder, a DS12887 chip, a 24 pin socket and a 6pF 32.768kHz crystal. This should be fun 😀

Thanks for the info.

cookertron wrote on 2020-03-23, 05:24:

The reason for doing this is for two reasons. The first is it'll be fun and the second is the battery will be the only thing that ever needs to be replaced.

I've ordered a CR2042 button battery holder, a DS12887 chip, a 24 pin socket and a 6pF 32.768kHz crystal. This should be fun 😀

Thanks for the info.

Out of interest, why the 12887 and not the 12885? Would save a lot of mess and give exactly the same result...

cookertron wrote on 2020-03-23, 05:24:

The reason for doing this is for two reasons. The first is it'll be fun and the second is the battery will be the only thing that ever needs to be replaced.

I've ordered a CR2042 button battery holder, a DS12887 chip, a 24 pin socket and a 6pF 32.768kHz crystal. This should be fun 😀

Thanks for the info.

If you ordered a DS12887, it will come with a brand new lithium batter inside the module. Replacing that would be a huge waste and the worst of both worlds. You get the cost of the complete module and the inelegance of the mod.

I'm noticing a weird ssue with Biostar MB-8433UUD, it came with a depleted Odin oec12c887a rtc, I changed it with a Dallas ds12887 with the cr mod, I noticed that the system is seldom booting fine while most of the times I got just a black screen.
The Dallas battery with the CR2032 mod is proved to work fine, then I swapped it with a Benchmarq bq3287AMT-1 with cr mod and with this one it works fine every time I boot it, is there a reason for such incompatibility?

Thanks

maxtherabbit wrote on 2020-03-24, 00:44:

cookertron wrote on 2020-03-23, 05:24:

The reason for doing this is for two reasons. The first is it'll be fun and the second is the battery will be the only thing that ever needs to be replaced.

I've ordered a CR2042 button battery holder, a DS12887 chip, a 24 pin socket and a 6pF 32.768kHz crystal. This should be fun 😀

Thanks for the info.

If you ordered a DS12887, it will come with a brand new lithium batter inside the module. Replacing that would be a huge waste and the worst of both worlds. You get the cost of the complete module and the inelegance of the mod.

Assuming he ordered it from a reputable electronics supplier and not from eBay, where the units offered tend to be >20y old and flat as an old bike tyre. Of course, why on earth you'd do that is another matter, but it happens...

dionb wrote on 2020-03-23, 07:18:

Out of interest, why the 12887 and not the 12885? Would save a lot of mess and give exactly the same result...

Not sure why I said 12887, I meant to say 12885!