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Possible fake Rockwell chip?
Posted: Wed Jul 28, 2021 8:11 am
by Cypress-25
I'm very new to the world of ICs so I'm unfamiliar with the meaning of the numbers on the top of the chip.
Anyway
I got a 6502 (not the CMOS version if that helps) chip from a local store with the markings
On it. All I've gathered is that it is a Rockwell chip, and couldn't fin much else.
On the bottom, there are some (painted?) markings that read
My questions are
-Could this chip be fake
-What do the ID numbers mean
-Where can I find correct datasheets for it
Thanks in advance!
EDIT: Added images, sorry for bad quality

- Bottom of the chip

- Top of the chip
Re: Possible fake Rockwell chip?
Posted: Wed Jul 28, 2021 8:36 am
by GARTHWILSON
Welcome.
You'll want to see our sticky topic, "65xx parts sources, genuine and fake." There, enso posted this link to an article that goes into detail about detecting counterfeits: https://www.aeri.com/counterfeit-electr ... detection/
Re: Possible fake Rockwell chip?
Posted: Wed Jul 28, 2021 10:45 am
by BigEd
Welcome, Cypress-25!
Long story short, pretty much any not-new 6502 could be fake, so you need to test it, and test in such a way that you don't risk damage to an old system that you value.
But as Garth notes, we have previous threads with guidance on these things.
Re: Possible fake Rockwell chip?
Posted: Wed Jul 28, 2021 4:39 pm
by Cypress-25
Okay, I'll be sure to read up on them.
Thanks so much for your help!
Re: Possible fake Rockwell chip?
Posted: Thu Jul 29, 2021 2:01 am
by jds
The markings look similar to other Rockwell chips I have seen, although they really vary a lot. I'm always suspicious of the really white large Rockwell logo ones.
The C014377 is an Atari part number, probably used in 400 or 800, newer 8-bit Atari's used a slightly modified 6502, labelled 6502C. It could also have come from an Atari disk drive.
The date code on the front, 8230 is the 30th week of 1982, which would be in the right date range.
R6502 is the part number, the -34 appears to be some sort of revision number or version number. So this should be a standard NMOS Rockwell 6502, the data sheet can be found on this very site
http://archive.6502.org/datasheets/rock ... _r651x.pdf.
Re: Possible fake Rockwell chip?
Posted: Thu Jul 29, 2021 8:02 am
by BigEd
(If the markings make no sense, that's a good sign of a remarked chip. It still might be a 6502! But if the markings do make sense, that could be fine, or it could be a relabelled chip. It still might not be a 6502! It might be that on the balance of evidence one would feel comfortable putting the chip into a system to see, but there's still a risk of damage. Setting up a NOP tester on a breadboard is a fairly cheap and easy way to gain confidence.)
Re: Possible fake Rockwell chip?
Posted: Thu Jul 29, 2021 8:54 am
by John West
The Atari part number was a good clue. Google images of Atari boards, and the 6502s on them look just like this one. The numbers will match whatever system Atari were using at the time, which is unlikely to be publicly documented. Apart from the "6502" and the date code, there's no reason to expect them to make sense.
The markings on that chip smell of the 1980s, the numbers look right, and it's from a local electronics(?) shop rather than an anonymous internet seller with no reputation to care about. I'd say it's likely to be genuine. It'll be a pull from a computer that possibly wasn't working, so what state it's in is the real unknown.
Re: Possible fake Rockwell chip?
Posted: Tue Aug 03, 2021 4:34 pm
by channelmaniac
Looks genuine to me.
Atari had a huge amount of components that were sold off when they closed up shop. One place in Santa Clara that bought a bunch was Anchor Electronics. I bought all their remaining NOS Atari 400/800 CPU and 16K RAM boards a few years ago. You'll find a lot of those chips still out in the market as there were reportedly 3 companies that bought up the majority of the stock. Best was another...