Counterfeit ICs
 

Hi,

For those who repair chess computers it is becoming increasingly difficult to find certain old integrated circuits. Although I'm using the new WDC 65C02 (at 14MHz) for repairs, I decided some time ago to buy a lot of 5 65C02 at 10MHz. They arrived yesterday, after two months. Well... they're fakes. With the tests that I've done and comparing details of the package with others I have, I think they're R65C02P4 (4MHz) re-marked with the reference 'WDC W65C02S8P-10' (10MHz)

The truth is that I was not surprised... is what I expected, but I wanted to try! because modern WDC is not always easy to adapt in older computers.

Well... In order that another incautious person does not fall into the trap, this is the seller:
www.ebay.com/usr/gowin_electronic

And this is the counterfeit 65C02:
http://www.ebay.com/itm/171526281785


Regards,
Gerardo M. (aka Berger)

AW: Counterfeit ICs
 

Hi Gerardo,
thank you for the warning and sharing your experience with us.

I'm not surprised too... It's nearly impossible to find WDC CPU rated 8 or 10 MHz. And as you already mentioned 14 MHz CPU W65C02S6TPG-14 doesn't work as an replacement in all of our chess computers...

But in some it does :) Possibly we can collect helpful infos on this topic. For Polgar it works, for MM IV and V also. For MC IV LE I was not able to get it run with correct display. I think it could be a timing problem.

Cheers,
Andreas

Re: Counterfeit ICs
 

Hi Drahti,

From what I've seen, this new WDC CPU is much more demanding with the system clock signal. The shape of the signal is important, especially the edges. I have solved some problems by improving the crystal oscillator, or by using one of the encapsulated type.

Also by the type of digital logic used: If the ICs used in the design are CMOS (eg 74 from the HC family) all usually work fine, but not when the design is very old and the ICs work with TTL signal levels. My worst experience, with chess computers, has been repairing Maestro SciSys modules!

Of course, you always have to keep in mind the differences with the old 65C02: pins 1, 5 and 36. ;)

Regards,
Berger

Re: Counterfeit ICs
 

Hello,

This case is even more stupid, as UMC did not manufacture any 6502 with the W65C02S8P-10 reference.

So this is an obvious counterfeit: https://www.ebay.co.uk/itm/293197724146

Regards,
Gerardo

AW: Counterfeit ICs
 

These chips have never been made by UMC. As much as I know the W65C02S8P-10 reference was only made by WDC.

I found another thread here:

http://forum.6502.org/viewtopic.php?f=12&t=4277

This chip seems not to be compatible with the additional 65C02 opcodes

And here: http://www.vcfed.org/forum/showthrea...vs-65C02/page2

a user said that this chip is not working in his old apple IIe. So whatever it may be, it is not a real W65C02S8P-10-compatible chip

Re: AW: Counterfeit ICs
 

Certainly. But unfortunately all the W65C02S8P-10 that can be found in Asia nowadays are also counterfeits. I have a box filled with counterfeit chips with this reference, bought in many different places: Most of them are Rockwell 'P4' re-marked.

The advantage of W65C02S8P-10 over the W65C02S6TPG-14, which is currently manufactured by WDC, is its greater compatibility with previous versions... which makes it easier to use for repairs.

Regards,
Gerardo

AW: Counterfeit ICs
 

Hi Gerardo,

for replacement of WDC 8 MHz CPU you can try to use Ricoh 6 MHz CPU. I "found" some Ricohs in several Mephisto Milanos. In Milano the original Ricoh can be replaced by any other compatible old CPU like Rockwell etc. or by a modern WDC 14 MHz.

Cheers,
Andreas

Re: Counterfeit ICs
 

Hallo,

These microprocessors, sold by a UK retailer via eBay, are also counterfeit.

https://www.ebay.co.uk/itm/W65C02S8P...Y/174151722133

Regards,
Gerardo