mark 8

3 Articles

Forget The Altair! Remember The Mark-8!

December 16, 2023 by 39 Comments

Calling any one computer the first hobby computer is fraught with peril. Most people think the MITS Altair 8800, first featured in Popular Electronics back in January 1975, was the first. Some might argue that others were first, but there is no doubt that the Altair started the hobby computer revolution from a practical standpoint. However, there was another computer that almost took the crown. It, too, appeared in a magazine — Radio and Electronics. But it was in the July 1974 issue. That computer was the Mark 8, and [Artem Kalinchuk] is building a replica that you can see started in the video below. This isn’t some Arduino work-alike. He has a pile of parts and some almost authentic-looking PCBs.

The Mark 8 used the 8008, not the 8080, so it was less powerful. [Artem] has been building a replica Altair, too. Check out his YouTube channel if you are interested in those.

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The Computer Of Yesterday, Today

June 27, 2017 by 16 Comments

There are a handful of computers that have become true museum pieces. The Altair, of course, is tucked away in the Smithsonian’s warehouse waiting for some time in the future when Apple’s legacy fades or until there’s a remake of War Games. Likewise, the French Micral and American SCELBI are important historical artifacts, and even a modern component-accurate reproduction of an Apple I could fetch a decent amount of cash at the right auction.

There’s something special about these old kit computers – even though the instructions for these machines provided volumes of documentation, no one is building these machines anymore. You just can’t buy the PCBs, and sourcing period-correct components is hard. [Brad] is an exception. He found original, untouched PCBs for the cover story of the July, 1974 edition of Radio-Electronics. It’s an unbuilt Mark-8 minicomputer. Now [Brad] is in a position no one else has been in since the 1970s: he can build a vintage minicomputer, with a TV Typewriter, from scratch. He’s documenting the whole thing.

Since this is the first opportunity this century anyone has had to build a truly retro minicomputer, [Brad] is going all-in with this project. For an interface, he’s building [Don Lancaster]’s TV Typewriter, a device introduced in the September 1973 issue Radio-Electronics. When combined with an old CRT TV, the TV Typewriter becomes a serial terminal. While today something like this could be built around a single microcontroller, constructing the TV Typewriter is no small feat: it’s spread across four boards, uses character generator ROMs, and is currently housed in a beautiful red oak case.

Just because [Brad] is building an ancient computer using ancient parts doesn’t mean he can’t get a little help from modern technology. He’s applying white silk screen to his custom TV Typewriter boards using the toner transfer process. Yes, apparently you can get toner cartridges filled with white (and neon!) toner, and this works well enough to replicate the look of professionally silk screened boards.

This is one of the greatest retrocomputing projects we’ve seen in a very long time. This is a true retrocomputer, complete with custom transformers and gigantic linear power supplies. When this project is complete, [Brad] will have a museum piece, all thanks to a lucky find of an eBay auction and a lot of hard work.

Mark 8 2016 Style

December 24, 2016 by 30 Comments

In the mid-1970’s there were several U.S.-based hobby electronics magazines, including Popular Electronics and Radio Electronics. Most people know that in 1975, Popular Electronics ran articles about the Altair 8800 and launched the personal computer industry. But they weren’t the first. That honor goes to Radio Electronics, that ran articles about the Mark 8 — based on the Intel 8008 — in 1974. There are a few reasons, the Altair did better in the marketplace. The Mark 8 wasn’t actually a kit. You could buy the PC boards, but you had to get the rest of the parts yourself. You also had to buy the plans. There wasn’t enough information in the articles to duplicate the build and — according to people who tried, maybe not enough information even in the plans.

[Henk Verbeek] wanted his own Mark 8 so he set about building one. Of course, coming up with an 8008 and some of the other chips these days is quite a challenge (and not cheap). He developed his own PCBs (and has some extra if anyone is looking to duplicate his accomplishment). There’s also a video, you can watch below.

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