Fake W65C02

From Leo's Notes
Last edited on 18 August 2020, at 15:59.
Fake Chinese W65C02 with everything wrong about them

I bought five W65C02 chips from AliExpress from a seller called 'Chuang Ming co. LTD Store'.  Tempted by the cheap price, I ordered a 5 pack. It shipped and arrived very quickly.

All of them were branded as WDC W65C02S8P-14 SA9908A. What struck me the most after receiving the package was that they were all wrapped together with plastic film without any ESD protection. Some pins were bent and all of them looked like they were dragged through the floor of a dirty warehouse.  I quickly rigged something up on a breadboard to test the chips. While they worked like a 6502, they did not seem to have the same reset as documented by Western Design Center's datasheet. WDC say it takes 7 cycles but the chip took 6.  It was pretty clear these were not legitimate WDC chips and are most likely recycled 6502 chips.

Taking a closer look, every package looked slightly different with the two dimples on the surface of each side located at slightly different location. Three of the five chips also have "TAIWAN" and a lot number of some sort printed on the underside while the other two were blank. One of the ICs had a smooth finish while the other had a very rough and worn look to it. Some of the leads also appear to be reworked or retinned because they had extra solder. One had a small chip in the corner of the package.

The process of recycling and remarking a chip is explained in Counterfeit Integrated Circuits:

A component is first prepared for remarking by either chemically or physically removing the original marking and then by blacktopping (resurfacing) the surface to hide any physical marks or imperfections that have been left from the marking removal process. False markings are then printed either by laser marking or ink marking onto the components to appear as though produced by the OCMs.
—Mark (Mohammad) Tehranipoor, Ujjwal Guin, Domenic Forte, Counterfeit Integrated Circuits, Detection and Avoidance

I was hesitant to open a dispute on AliExpress since the chips were only about $6 with shipping but I eventually did. Surprisingly, the seller did not respond to the dispute and AliExpress refunded the full amount after the dispute window expired.

See Also