Punch Cards

Before the Commodore 64, the IBM PC, and even the Apple I, most computers took input data from a type of non-magnetic storage medium that is rarely used today: the punched card. These pieces of cardstock held programs, data, and pretty much everything used to run computers in the before-time. But with all of that paper floating around, how did a programmer or user keep up with everything? Enter the punch card sorter and [Ken Shirriff[‘s eloquent explanation of how these machines operate.

Card sorters work by reading information on the punched card and shuffling the cards into a series of stacks. As [Ken] explains, the cards can be run through the machine multiple times if they need to be sorted into more groups than the machine can manage during one run, using a radix sort algorithm.

The card reader that [Ken] examines in detail uses vacuum tubes and relays to handle the logical operation to handle memory and logic operations. This particular specimen is more than half a century old, rather robust, and a perfect piece for the Computer History Museum in Mountain View.

It’s always interesting to go back and examine (mostly) obsolete technology. There are often some things that get lost in the shuffle (so to speak). Even today, punched cards live on in the automation world, where it’s still an efficient way of programming various robots and other equipment. Another place that it lives on is in voting machines in jurisdictions where physical votes must be cast. Hanging chads, anyone?

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The Man Who Didn’t Invent The Personal Computer

[John Blankenbaker] did not invent the personal computer. Museums, computer historians, and authors have other realities in mind when they say [John]’s invention, the KENBAK-1, was the first electronic, commercially available computer that was not a kit, and available to the general population.

In a way, it’s almost to the KENBAK’s detriment that it is labelled the first personal computer. It was, after all, a computer from before the age of the microprocessor. It is possibly the simplest machine ever sold and an architecturally unique machine that has more in common with the ENIAC than any other machine built in the last thirty years..

The story of the creation of this ancient computer has never been told until now. [John], a surprisingly spry octogenarian, told the story of his career and the development of the first personal computer at the Vintage Computer Festival East last month. This is his story of not inventing the personal computer.

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Don’t Tempt the Demo Gods

Including a live technical demonstration as part of a presentation is a lot like walking a tightrope without a net. Which isn’t to say that we don’t do it — we just keep our fingers crossed and bring our lucky horseshoe. The demo gods have smote [Quinn] a mighty blow, in front of a class at Stanford, no less.


[Quinn]’s scratch-built computer, Veronica, failed to boot in front of a hall of eager students. When the pressure was off, in the comfort of her own lab, [Quinn] got to debugging. You should read her blog post if you’re at all interested in retrocomputing or troubleshooting of low-level hardware bugs. But if you just can’t spare the five minutes for a pleasant read, here’s a spoiler: watch out for flaky card-edge connectors. All’s well that ends well, with a game of pong.

We’ve been following Veronica from her very first clock cycles, so we’re happy to see her back on her feet again. Good job, [Quinn]!

Dump Your (Old) Computer’s ROM Using Audacity

If you’ve got an old calculator, Commodore 64, or any other device that used a tape recorder to store and retrieve data, you’ve probably also got a bunch of cassettes lying around, right? Well, you can get rid of them now (or sell them to nostalgic collectors for outrageous prices) because you can just as easily dump them to Audacity, decode them and archive them on a more sane medium.

In [Kai]’s case, the computer was a Sharp Pocket Computer system, and in his post there’s a lot of detail that’s specific to that particular system. If that’s applicable to you, go read up. In particular, you’ll be glad to find that the Pocket-Tools is a software suite that will encode and decode files between the Sharp binary formats and audio. Along the way, we found similar tools for Casio pocket computers too.

For a more general-purpose approach, like if you’re trying to dump and load data from a more standard computer that uses 1200/2400 Hz FSK encoding, this Python library may be useful, or you can implement the Goerzel algorithm yourself on your platform of choice. If you’ve got a particular binary format in mind, though, you’ll have to do the grunt work yourself.

Anyone out there still using these audio data encodings? We know that ham radio’s APRS system runs on two tones. What else? Why and when would you ever transfer data this way these days?

via the Adafruit blog!

Hackaday Teams with Vintage Computer Festival for Retro Hackathon

For the last few years, we’ve been going to the Vintage Computer Festival East in New Jersey. This is one of the best cons we go to every year; there are dozens of interesting exhibitors, awesome talks, a great venue, and a small consignment area filled with the weirdest stuff you can imagine. This year proves to be no different, and we’ll be there cataloging the weirdness and spectacular hacks of computer systems old enough to vote, plus something new.

Hackaday’s 8-bit game programming contest is happening for the first time at VCF East, April 15-17 in Wall, New Jersey. Competitors are given two and a half hours and an old 8-bit system (Apple II, C64, Atari 800, etc.). The goal is to create a game using only what is currently in memory, be that in the ROM or between the ears. There are two sessions on the Friday of the event, starting at 10am and 2:30pm.

You can call the 8-bit game programming contest a hackathon. That’s basically what it is; getting a small team together to whip up an application quickly with a number of constraints. The term ‘hackathon’ has been bastardized as of late, with companies requiring the use of a particular API or other nonsense. The 8-bit programming contest doesn’t have these limitations. All you need to do is create the coolest game in two and a half hours, and get the most applause from the audience. The best game wins a prize.

Of course, we’re not going to VCF East just to promote a retro hackathon. We’re only obliged to mention that first because we’re sponsoring it. VCF East is a fantastic event, with more retro goodies to satiate even the most curmudgeonly retro aficionado. The show is enormous with keynotes from [John Blankenbaker], inventor of the Kenbak-1 personal computer and [Stewart Cheifet], host of Computer Chronicles. Dr. Dr. Ted Nelson, author of Computer Lib and creator of Xanadu, the underlying software for computers that won’t be built for 100 years, will also be there. The weekend is, as always, packed with great exhibits of ancient tech, classes, and workshops.

Each Vintage Computer Festival is different, but if you’d like a sample of what it’s all about, check out these posts:

Apart from an announcement for the festival in New Jersey, there are a lot of changes in the organization of the various vintage computer festivals held around the country. The Vintage Computer Festival East was formerly organized by MARCH, the Mid-Atlantic Retro Computing Hobbyists. Late last year, MARCH was dissolved, and reformed as a 501(c)3 called the Vintage Computer Federation. The VCF (see what they did there?) also has the rights to hold VCF West, which last happened in 2007. The VCF Midwest, Southwest, Europe, and UK will remain independent.

If it isn’t already extremely obvious, this is one of the top-tier events we go to every year. No, it’s not DEF CON, it’s not HOPE, and it’s certainly not a big con. It’s just a bunch of nerds nerding out, which is the critical ingredient for the best events we attend all year.

Breadboard Colecovision

The Colecovision was a state-of-the-art game console back in 1983. Based around the Z-80, it was almost a personal computer (and, with the Adam add-on, it could serve that function, complete with a daisy wheel printer for output). [Kernelcrash] set out to recreate the Colecovision on a breadboard and kept notes of the process.

His earlier project was building a Funvision (a rebranded VTech Creativision) on a breadboard, so he started with the parts he had from that project. He did make some design changes (for example, generating separate clocks instead of using the original design’s method for producing the different frequencies needed).

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My Payphone Runs Linux

For the 20th anniversary of the Movie “Hackers” [Jamie Zawinski], owner of DNA Lounge in San Francisco, threw an epic party – screening the movie, setting up skating ramps and all that jazz. One of the props he put up was an old payphone, but he didn’t have time to bring it alive. The one thing he didn’t want this phone to do was to be able to make calls. A couple of weeks later, he threw another party, this time screening “Tank Girl” instead. For this gathering he had enough time to put a Linux computer inside the old payphone. When the handset is picked up, it “dials” a number which brings up a voice mail system that announces the schedule of events and other interactive stuff. As usual, this project looked simple enough to start with, but turned out way more complicated than he anticipated. Thankfully for us, he broke down his build in to bite sized chunks to make it easy for us to follow what he did.

This build is a thing of beauty, so let’s drill down into what the project involved:

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