necroware / nwx287 Goto Github PK

Hi, my friend, can I solder the crystal in any way or the xtal has a like + and - side like capacitors? (sorry my nob question about crystals)
I have ordered some from alliexpress and they some have no marking and the legs are the same size.
In the photos you supplied I can see that some lettering in them, but could be coincidence .
Thank you!
Jorge

you don't list the Turned pins that are used on the unit also not in the BOM do you have a description for which pins you used?

Hi,

Awesome job you did here, big thanks!

I want to order the components, but I see an issue. Readme calls for CR1220 / CR1225 battery holder while the silk screen layer has CR2025 marking.

So just to be sure, which is it? Or do all of those battery holders fit on the PCB?

Thanks!

Does it replace DS1386-8K-120 or DS1386-8K-150 ?
These have 8KB of NVRAM.

chips have the same code in kicad schematic

Hi,

Could you share your project directly on PCBWay (https://www.pcbway.com/project/shareproject/) ?

It would be easier to order PCBs and you could get some money too ;-)

Regards,
Xavier

First of all, thanks for this project. Looks like it's exactly what I need, and I appreciate the effort.

I have ordered a nwx287 to replace a Dallas DS12887.

I'm unsure about this:
"Important: some mainboards seem to use /RCL pin 21, so cut it first if you are sure, that your mainboard doesn't use it."

Is there any safe way I can find out if my main board uses the RCL pin or not?

Any risk not cutting and, and testing first?

The machine is a DEC Venturis 5100, Pentium 100, SIS 5501 chipset.

Text on Dallas module:
Dallas
DS12887
REALTIME
9538A2 067579

Hello !
Do you think it could work with the Dallas DS14287 ? I suspect the Benchmarq BQ4287 is a clone of that Dallas but I'm not 100% sure it's safe to try. Can you tell me ?
If it's safe I'll try it and report back :)

The first bootup's are fine but then I always get this "CMOS Inoperational - System halted" error.
When I remove the battery (CR1220) for some time and reset it in the error is gone.

It is a replacement for a Dallas DS1287 in a 386-SX Laptop (Walkom / NoteStar NP-903).

The nwX287 uses a DS12885S RTC chip.

Any hints what could be wrong?

My Soyo SY-5VA motherboard had a dead VIA VT82887. I've tried a DS12887a and I've found it is not compatibile, it always gives a checksum error.

I've tried the nwx287 and it works!

Hi all.

I assembled an RTC-Module with the nwX287 PCB and a BQ3285S RTC.

Now I am getting the "cmos checksum error defaults loaded".

The Battery Error is not indicated and the battery is fresh and has voltage.

I testet

• Loading BIOS or Setup defaults

• Flashing the BIOS with the latest (WI7C 040197) Award from theretroweb

• Checked continuity on all pins and legs on the RTC Module

What I noticed was that the time drifted forward and the seconds where erroraneous.

It goes like this: 1 - 19, 40, 0

What is going on here? Did I use the wrong RTC Chip?

May it be a counterfeit?

Did I damage it because it got a bit hot during soldering?

Can I rule the BIOS EEPROM out since it should be an issue with the RTC?

I have the original ODIN OEC12C887. Should I mod it to rule the BIOS EEPROM out?

It may be evident, but there are also crystals available with 32.000kHz. So better put the right value in the schematic

Recently I have had produced some PCBs using your fantasic dallas clock module replacements. I'm now in the process of assembling one module. It seems there is no (identifieable) pin 1 marking on the silkscreen for the clock chip. Looking around it seems that pin 1 is towards the crystal. To make thinks clear please add a marking on the silkscreen.

Thanks alot and have a nice 2024.

Unfortunately doesn't work (Alaris Cougar)...

Hi,

Awesome job you did here, big thanks!

I want to order the components, but I see an issue. Readme calls for CR1220 / CR1225 battery holder while the silk screen layer has CR2025 marking.

So just to be sure, which is it? Or do all of those battery holders fit on the PCB?

Thanks!

I'm fairly new to KiCad. Actually, I just installed it. I do use Altium for work, though.

It seems the symbol cache is missing.

Datasheet says that 3285S is low power but maybe not like as (L)CS ?
whats difference?

Examplary SRAMs memories not marked as L, drains battery quickly

Hello.

Out there are multiple versions of the Dallas RTC chip, among them the DS12B887 and DS12C887

How does it looks with the compatibility? I have tried various alternatives I could find online and they didn't worked on my systems.