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Are Dallas DS12887A & DS12887+ interchangeable?

I responded to your message on Tindie, did you not receive the reply?

Oh crap, I only checked here. My bad brother. I already ordered from you regardless. Looks like there are direct replacements for the DS1225Y from numerous sources. My only confusion was some are 200ns+ and some are 150ns+, but I was told either should be fine for a machine from 1992 as my DS1225Y has no markings indicating the ns. Thanks for your excellent product by the way!!!
 
You're welcome! The best way to get in contact with me is always through the contact link on my website -- that goes to an email address that gets checked throughout the day.

There are certainly new DS1225s available from reputable sources, just don't buy one from China expecting it to be any good. I've bought numerous clock/NVRAM modules from China to destroy and reverse engineer, every single one has been a relabel with a mostly dead to totally dead battery. When I buy a replacement module for something I haven't created a maintainable alternative for, I always buy from Mouser -- I'm sure Digi-Key and the other big names are equally reliable.
 
You're welcome! The best way to get in contact with me is always through the contact link on my website -- that goes to an email address that gets checked throughout the day.

There are certainly new DS1225s available from reputable sources, just don't buy one from China expecting it to be any good. I've bought numerous clock/NVRAM modules from China to destroy and reverse engineer, every single one has been a relabel with a mostly dead to totally dead battery. When I buy a replacement module for something I haven't created a maintainable alternative for, I always buy from Mouser -- I'm sure Digi-Key and the other big names are equally reliable.

Thanks for the info because the Chinese parts are tempting because of price and yes, I found Digikey has direct replacements for them.

https://www.digikey.com/products/en...tity=&ColumnSort=0&page=1&stock=1&pageSize=25
 
Yeah, Chinese resellers are often half the price, or less -- that's why I used them for destructive analysis! Mouser has the same modules for around $20/ea; of course, if you're already ordering from Digi-Key, the separate shipping would cancel out any savings.
 
I've built a few ALT12887's for some of my machines that need them. Fun little project, but with the cost of the PCBs and then the cost of the parts from digikey or mouser, ultimately it would be cheaper just to buy a 12887 or one of Glitch's kits, but the alt12887 is kind of fun practice for SMD soldering ;-)
alt12887.jpg
 
Yeah, I looked at the ALT12887 before doing the GW-12887-1 -- figured that using a DIP DS12885 and bending the pins up (which is how the Dallas/Maxim DS12887 is made) was not only cheaper, but easier than dealing with header pin alignment. You also don't have the issue of trying to put round pins into a socket that expects flat DIP pins, if there's already a socket in place.
 
Yeah, I looked at the ALT12887 before doing the GW-12887-1 -- figured that using a DIP DS12885 and bending the pins up (which is how the Dallas/Maxim DS12887 is made) was not only cheaper, but easier than dealing with header pin alignment. You also don't have the issue of trying to put round pins into a socket that expects flat DIP pins, if there's already a socket in place.

I wasn't lucky enough to have any sockets in any of my DS12887 machines, they all had to play hardball with soldered chips, so I've installed nice machine pin sockets in all of them now, the ALT12887's have worked very well in those sockets for me.
 
Why not simply dig into the epoxy and solder in a new battery? Even for those boards with soldered-in RTCs, it isn't that difficult.


I've done the mod before too, I built the ALT12877's because I was short a few Dallas chips, I totally butchered one doing the mod, got a little overzealous with the Dremel, and another one I had didn't work at all, even before the mod attempt, so I was short 2 of them for the systems I had.
The 3rd ALT12887 I built went into a laptop, there was not enough clearance in the laptop to do my normal "battery holder hot glued to the top of the Dallas chip mod", and it was pretty limited in places I could mount a battery holder elsewhere, so the ALT is a good fit for that, it is lower profile than even the original Dallas chips (from the looks of it Glitch's solution is too).
 
The GW-12887-1 is about the same height as the original Dallas module, I forget if it's slightly shorter or not.

For me, the purpose of these repair boards is that it's much faster for me to repair a bunch of dead modules at once with them. I can make a few quick cuts with the hack saw, the way I do it actually *requires* cutting the old leads instead of being careful around them. I pull the modules and replace with sockets anyway, with the Hakko 472D desoldering station, it's very easy.
 
The GW-12887-1 is about the same height as the original Dallas module, I forget if it's slightly shorter or not.

For me, the purpose of these repair boards is that it's much faster for me to repair a bunch of dead modules at once with them. I can make a few quick cuts with the hack saw, the way I do it actually *requires* cutting the old leads instead of being careful around them. I pull the modules and replace with sockets anyway, with the Hakko 472D desoldering station, it's very easy.

Yeah a desoldering gun is on my short list of things to get, I have been using braid, that's a pain in the butt to desolder a chip like that LOL
 
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