nw12887
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Drop-In replacement for Dallas DS12887 RTC module
Necroware's NW12887 RTC module
ATTENTION: this project was made for the SSOP-24 version of the RTC IC, if you need the SO-24 version go for https://github.com/necroware/nwX287 project instead
This is a drop-in replacement for RTC modules with solid body. Such modules were widely used on 486 and Pentium mainboards back in the days. After so many years the battery inside of such modules got empty and there is no way to exchange it. With empty battery BIOS settings can not be saved and so many mainboards can't even boot properly. This alternative solution has a socket for CR1225 and the battery can be easily replaced again, when it gets empty.
This part should be compatible with following RTC modules:
- Dallas DS1287 / DS12887 / DS12B887
- Benchmarq BQ3287
- ODIN OEC12C887
Bill of Materials
Part | # | Description |
---|---|---|
U1 | 1 | Real-Time Clock BQ3285LDSS SSOP-24 |
Y1 | 1 | Crystal oscillator 32.768kHz 6pF |
BT1 | 1 | CR1220 / CR1225 SMD battery holder |