intel C4004 barn find

[thousandparadox]

Hello everyone.
I don't quite know how to approach this post, or if it's in the correct category.

I recently found that I had a C4004 and other 4000 series Intel chips in one of my part’s drawers.

The chips are marked:
4002-2
4002-2
4004
4008
4009
1602A
1602A

Here are the images:
https://imgur.com/a/NIFKG9l


Here is the story of how I came into possession of these rare chips:
It was around the year 2012. I was going to community college and I volunteered/worked at a
computer recycling charity that fixed up old desktops to be donated to people in need. Upstairs
was an electronics workshop that belonged to one of the board members or founders, a retired
electrical engineer. I spent a lot of time up stairs, testing and repairing items for resale on Ebay
to help fund the non-profit. I wanted to study to become an electrical engineer and so, wanted
to befriend the owner of the lab. He was in his 80’s, and unfortunately I only met him twice
before he passed away. He had given me a basic V = I * R type electronics homework to help
teach me, but I never was able to turn it in. Some of his friends came and took away his oscilloscope
and other lab equipment. Thereafter I became the custodian of what was left of the electronics lab.
Like any good electronics lab it had many tiny parts drawers full of misc parts. It was in these drawers
that I found the 4004 and other interesting old chips. Not thinking they were worth anything more
than a curiosity, I took them home along with vacuum tubes, EPROM chips with the little windows,
and 1980’s newspaper clippings of Mac-IIs for sale.

Eleven years later, I was talking to a friend about some old chips he had, which prompted me to
dig up what I had. Looking at the chips closely again I decided to look up the numbers that were
scratched on these mostly blank chips, and discovered what they are. Now here I am, trying to decide
what to do next. I have known about the story of the original Intel 4004 CPU for years, but I never
thought I had such a thing buried in my parts drawers...


The five chips are hand marked and have no hint of an original intel marking on the top or bottom.
Despite the lack of marking, the rest of the chip looks identical to pictures found on cpu-zone.com.
I used my microscope on the EPROMs, and the dies are both marked Intel 1602A.
It's a shame the 4004 is the only one that has it's gold coating peeling, but I guess it gives it character.


My interest is in selling them, hopefully to someone who wants to repair a vintage machine or build
a custom board with the 4004 and the rest of the chipset. I know the 4004 might be worth an
uncomfortable amount of money, so any advice on what you think they are worth, and how I should
go about selling them is appreciated.

Thanks

[rjluna2]

Nice find
The 4002 is RAM plus I/O port.
The 4008 and 4009 are memory plus I/O port.
These 1602A are probably 1702 EPROM.

https://en.wikipedia.org/wiki/List_of_Intel_processors#Intel_4004

[crazybubba64]

Given that the parts are completely unmarked, you may have something very special there.

These may be prototypes/samples or reject parts that got "recovered".

Certainly not a run-of-the-mill C4004!

[thousandparadox]

I have been thinking about if they could be engineering samples.
Even samples should have SOME marking right? It would seem like instant disaster
of confusion if intel did not mark them. Images on CPU-zone suggest that the earliest units
had the "grey traces" visible inside the ceramic, so I would guess engineering samples
would have the same look.

It is possible these are rejects that were never stamped in order to prevent them from
getting mixed into the official pool. perhaps they were given away as gifts?


My working theory is that the intel C4004 label had faded over time. Seeing this happening,
the person removed the label completely with solvent and scratched the numbers into place.
That might explain why ALL the chips are blank. The thought might have been: it would
only be a matter of time before they all completely faded. better finish off all the labels
and rewrite them with something more permanent.


My 4004 looks just like this picture on cpu-zone: https://www.cpu-zone.com/4004/DSCF0172.JPG
and on cpu-galexy: https://www.cpu-galaxy.at/cpu/Intel%20CPU/3002-8008/C4004_NDC_two_lines.JPG
A. Same size lid size and corner shape,
B. Same pin1 "Lo" mark style
C. Same ceramic geometry
D. no date code on the bottom (N.D.C)
Of course, mine have no label, but both the images from zone and galaxy have slightly faded labels compared to the other C4004s they have pictured...


I wonder if I should buy or build some sot of tester to confirm what they are.

[debs3759]

It's also possible that they had weak print that lifted off because of some process they went through after the original sale, if they are indeed what the scratched text says. They really need to be tested by someone to confirm what they are, then they'll be worth more. Nobody wants to spend much on a possible early fake.