(Topic ID: 287358)

WPC-98 Cap ID please

By darowla

10 months ago

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  • 15 posts
  • 5 Pinsiders participating
  • Latest reply 8 months ago by G-P-E
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Bad Clocks (resized).png
32KHz Clock Signal (resized).png
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#5 9 months ago
Quoted from darowla:

What would u repalce them with?

This is a complete WPC89 parts list I made MANY years ago ... some parts may no longer be available.

It contains links, costs, units per assembly for every part on the board from Mouser Electronics. ... I would be happy to add links to G-P-E parts if you would provide them to me.

I put this together mainly for my self for supply acquisition and record keeping as I already had ALL of this information available from manufacturing a few boards.

#8 9 months ago
Quoted from darowla:

I just want to see a decent 32khz signal on my scope

The Yellow trace is from a board built using ALL new components as listed in the parts spreadsheet; the Cyan trace is from a fully functional WPC089 board mfg in 1992.
32KHz Clock Signal (resized).png

#10 9 months ago
Quoted from barakandl:

I am not sure if it is exists with this RTC but usually look for an external clock on the CPU. It is a better place to check if the clock is working.

There is no external clock for this; this is nothing more than a clock frequency for the real time clock (RTC), the processor itself doesn't care if it there at all, fast, or slow...it only controls the rate at which the clock keeps time...if you make this a 64KHz clock your game will play fine but the RTC will run twice as fast.

I actually tested this for someone who has a wrong resister installed in the RTC circuit; those clocks looked like the yellow waveform shown below in Channel 1 compared to a the correct 32KHz clocks stored in memory (Green Channel).

Bad Clocks (resized).png

This frequency was very unstable as the RTC circuit was not designed to operate at this frequency.

pasted_image (resized).png

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