We all know that fake chips are a risk when it comes to buying parts on eBay or from Chinese markets such as AliExpress. It’s a simple enough scam, take a cheap chip and mark it as an expensive one, pocket the difference. It’s happened in several different forms, with everything from completely different devices through cheaper equivalents to incredibly, chips purpose fabricated to emulate better-known ones. We have a chance to see such a scam in action via [LinuxJedi], with a 6502 that wasn’t quite as it seemed.
The chip in question was a Rockwell 65C02 destined for an Acorn Atom, and when installed it failed to deliver the expected power consumption saving. Unsurprisingly when tested it turned out to be a fake, in this case a run-of-the-mill 6502 with new markings. The interesting part for Hackaday readers comes in the physical clues. The too-bright markings started to dissolve with a bit of acetone. A deeper investigation revealed the date and wafer codes did not agree with the branding. A new chip was secured which also turned out to be a fake, though in this case a real 65C02 rated for a lower clock speed than marked.
It’s evident that in-demand retro chips are likely to be an ever-greater minefield of fakes as time passes, and the number of survivors dwindles. It’s as well to be aware then and learn from any fakes like these posted online. It’s not the first fake chip we’ve brought you.
That title is a bit misleading, as both discussed parts in the article are indeed 6502s – just not the exact part which was labeled.
The Chinese company GeneralPlus still makes 65c02 cores, as part of its line of 8-bit microcontrollers. It’s a little hard to figure out which ones because they never mention the CPU architecture by name in their datasheets, and some of their products use 8051 cores.
It seems they don’t really sell discrete parts but instead make custom solutions for large customers. I found a 65c02 in a relatively recent VTech toy, for example. It’d be really cool to find one of their products which _could_ be bought in small number of units and could be repurposed as general-purpose CPUs…
There is a lot of counterfeit stuff coming from china. Look out for 2TB memories, especially USB Flash drives, and SD memories. They are hacking 32GB memories, and reprogramming them to think they are 2TB memories. When you write a little data to them, they store it correctly, but if you try to write more than 32GB of data to them, they start over writing the data first written into the memory causing read failures. It’s a sneaky organized crime thing. Be careful as to who you buy your chips from. There’s a lot of organized crime in the Chinese semiconductor industry.
This is an old scam. But when I got hit it was a 512mb disguised as 8GB
This is older than the internet
This was even a thing with 128gb USB thumb drives years ago.
Bonus points if they installed some malware as well. I remember a local store selling a batch of those.
I’ve ordered dozens of 6502s from shady Chinese sources and the chance of getting a remark or outright fake seems to depend on what you’re ordering. A 1MHz 6502 or a 2MHz 6502A and you’ll probably get the right chip, these were very common back in the day and the Chinese junk recyclers probably have stacks of them.
3MHz 6502Bs are rare as hens teeth and you’ll absolutely get a remark, though it may be hard to tell without using acetone because most 1980s 6502As will run at 3MHz just fine.
I’m not surprised by LinuxJedi’s experience, the most commonly remarked models are the Rockwell and UMC 65C02s. Those are popular because they’re drop-in replacements for old NMOS 6502s that reduce power consumption, fix some bugs and implement a few useful new instructions. If you order a 65C02 it’s mainly a question of what you’ll actually get; an NMOS 6502, a lower speed grade 65C02, or an outright fake part that has nothing to do with a 6502. But you can get lucky.
Some months ago I ordered a pair of supposed 4MHz Rockwell 65C02s from a vendor with a good reputation. One chip was completely dead and from what I could gather is probably a failed NMOS 6502 under the fake markings. The other chip amazingly seemed to be a real 65C02 that happily ran as fast as 5MHz with no issues, so I suspect it’s a genuine 4MHz 65C02 as the Rockwell chips don’t have much headroom over their marked clock typically.
It’s also worth noting you can buy brand new 65C02s. Western Design Center still produces them and Mouser stocks a variety of parts. But the WDC chips are not drop-in replacements for old 6502s, there’s a little bit of bodging involved. At minium it needs a pin lifted and tied to VCC with a resistor. But you do get the assurance of a brand new, functioning chip that’s rated to 14MHz.
Is there really a reason for buying old 65c02 ICs when you can buy brand new ones?
Westerndesigncenter bought all the licenses and build them brand new, they sell via official distributors like mouser.
The old Rockwell and UMC 65C02s are drop-in replacements for standard 6502s, but the modern WDC chips are not. The pin-out is a different enough to be a minor headache. Also, all the older 6502/65C02 chips will accept 3.3v signals when the chip is running at 5v, but the WDC chips will not. That can cause issues in machines with modern add-ons based on 3.3v logic.
So there are definitely cases where taking the risk buying an old chip makes sense.
Thanks for that explanation, i was unaware of the differences!
In addition to surface-level physical differences, such as pin function and voltage tolerance, 65C02 chips made by different vendors or in different eras have different instruction sets.
I often get a batch with all the same markings but packages obviously from different manufacturers.
Sometimes I get a 65C02 with 6502A on the label.
Honestly I think it’s more a case of wanting to “send what’s in the photo” rather than trying to maliciously pass something with a lower rating off as a higher one.
I really wish all those listings would just be for “some sort of 6502” but with original markings :/
I have a feeling most R6507s I get are UM6507s – since they’re suspiciously missing Rockwell font on the bottom. But they mostly perform the same so I don’t mind in that case.
How do you say caveat emptor in Chinese?
Amazon.
…also translated as AliExpress
I laughed. :)
The 6502 was the first instruction set I learned. What are people using this 8-bit chip for? Is this a hobby thing or are their real products being made? And how much do these things cost now-a-days?
Surpisingly you can still buy variants of this chip new. Sadly not drop-in compatible but with a small adapter board it should be possible to use them.
I would thing by now people would just use implementations on fpga. Should work just as well as an original.
I see al lot of videos these days for building “new” c64’s almost every part of that has an fpga replacement that fits in the dip sockets.