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X-rated Processors

Summary: Lusting for those early microprocessor days? Here's a site guaranteed to sate your passion.

My wife and I joke about our "adult" magazines. For her, those are the publications about beading. For me, they're tool catalogs and Fine Woodworking magazine. The latter I peruse as avidly as a teenager gazing at an illicitly-procured Playboy (or, whatever passes for those sorts of magazines today).

And yes, I do read the articles.

Then there's processor porn. Do you want to see thousands of pictures of naked CPUs? Stop by the CPU Shack ( In addition to extensive archives of processor pics, the site weekly struts out different bits of silicon technology from the past. As in the aforementioned Playboy, the CPU of the Week gets a complete description, though the figures tend towards bus size and clock speed rather than other sorts of dimensions.

For the high-minded who scorn prurient pictures, the site does have articles which are well worth reading.

Hopefully I'm not overstepping the anti-obscenity policy here at, but this is a hot processor picture from CPU Shack. It's Intel's 3002:

I well remember this device. The description says this nerd-magnet was born in 1973, which is astonishingly early. It's a bit-slice processor - a two bit slice of a computer. String together as many as you want to get whatever bus size is needed. Strange, huh? AMD competed with the 2901, a 4-bit slice, with which we designed some high-end graphics gear long ago. I don't know how popular the 3002 was, but the 2901 gained wide acceptance.

Then there's this sweet thing, a 4004, the first commercially-successful microprocessor:

Yes, at 44 years old the old thing has a few nicks and a fading appearance. For younger readers let me assure you that looks aren't everything, and in this case the old gal is still a hottie.

We all know how Intel was asked to design a calculator chip set, but decided to do a general-purpose computer instead. What is less well known is that the company figured that, while a computer IC would be a nice sideline, it would more importantly increase demand for their memory chips!

The 4004 was built of 10,000 nm geometry on 2 inch wafers. You can still buy them. As of this writing a few 4004 chips are up for bids on eBay. One is currently at $1200. for a four bit CPU that was obsolete 40 years ago. It came out for about $100, or $600 today. Obviously, these are historical artifacts priced accordingly. It is interesting, though, that their price reflects the opposite of Moore's Law.

Turns out, there's quite an interest in retro computing, and John Culver, curator of the CPU Shack, has introduced a board for testing your collection of 4004 and 4040 microprocessors. The following flagrant violation of's anti-NSFW policy is a picture of the "bare board" that constitutes the MCS-4 Test Board:

Pretty darn sexy, if you ask me.

Actually, it comes fully-clothed, ah, assembled, so isn't exactly a "bare board."

The MCS-4 tester also checks 4040 devices, a souped up four bitter than came out in 1974. These, too, are available on eBay, and I see one at the moment with a $75 "buy it now" price. For that one could get a couple of hundred Cortex M0 32 bit processors, replete with gobs of memory and I/O. Each of those could run circles around the 4040.

The MCS-4 tester will also let users run their own code on the 4004 or 4040 (CPU chip is not included). A 28C64 EEPROM stores the code. You'd need a programmer for the EEPROM, as the board can't load code into the memory chip.

John tells me that he sold out his first batch in a week, but more are on order. Some of his customers just want to check the functionality of their museum-piece CPUs. Others use them in retro projects, like a nixie tube clock. (Nixie tubes were the vacuum-tube equivalent of seven-segment LEDs back in the olden days when engineers weren't afraid to tread in voltage domains above 5V.)

Calendars that sport monthly pictures of attractive pin-ups famously grace the grubby walls of garages. I wish John would come out with a calendar for techies that featured a hot processor of the month!

Published February 3, 2015