Differential Analyzer Cranks out Math like a Champ at VCF 2016

Here at VCF, we stumbled across a gigantic contraption that spanned several tables. Rube Goldberg machine this was not. Instead, this device actually does something useful! [Tim Robinson’s] differential analyzer can solve differential equations through several stages of mechanical integrators. The result is a pen-plot graph of the solution to the input equation, input by displacing a rod as a function of time.

Differential analyzers have been around for over a century. [Tim’s] claim to fame is that this particular DA is constructed entirely from Meccano-branded parts. We’re thrilled to see Meccano, over 100 years old at this point, continue to find new uses outside the toy box.

The Torque Amplifier

The differential analyzer is riddled with mechanisms that are bound to swing some heads for a double-take. Since the input shaft that transmits the input function f(x), has very little friction, the result can only be carried through the remainder of the machine with some means of torque amplification. To do so, [Tim], and most other DA designers implement a torque analyzer. For [Tim], though, this feat proved to be more difficult (and more triumphant) than other solutions, since he’s using a set of parts that are entirely from Meccano. In fact, this feature took [Tim] through about 20 iterations before he was finally satisfied.

VCF West continues to run through the end of the weekend at the Computer History Museum in Mountain View, CA. If you haven’t already packed your bags for DEF CON, stop by for a few more bewildering brain teasers.

Join Us at Vintage Computer Festival West This Weekend

VCF West is happening this Saturday and Sunday at the Computer History Museum in Mountain View, CA. This on of our favorite events; a celebration of the hardware that paved the way for our modern world. VCF attracts an impressive amount of rare and interesting computers and other technology items. That hardware doesn’t make it to the festival on its own. The people at VCF — exhibitors, speakers, attendees, etc — are themselves an incredible collection of stories from salvage and restoration to the inside story on the teams that made the computers in the first place.  Check out some of Brian Benchoff’s coverage of VCF East earlier this year.

VCF_coverI ran into Vintage Computer Federation President Evan Koblentz ten days ago and he shared an interesting anecdote I think you’ll enjoy. Bil Herd was a featured speaker at VCF East a few years back. He was the Senior Design Engineer behind the Commodore C128 — obviously a fascinating person to headline the event. The year after Bil spoke at the festival, Evan as surprised to run into him wandering around the event again. Bil didn’t just want to speak, he wanted to see all the cool stuff and has attended, spoken, and conducted workshops at several of the festivals since.

Who will show up this year is anyone’s guess. But we know this event is incredible and you will be amazed at who you run into. It is important to recognize where our technology comes from, to celebrate those who made it happen, and to encourage young people to start on the path to becoming a computer engineering wizard. For all of these reasons we are happy to be sponsoring VCF West. On the inside cover of every festival program you’ll find this epic art by our Illustrator, Joe Kim. You can also click the image on the right to embiggen.

Joshua Vasquez will on hand for Hackaday at VCF West. He’s looking for the best bits to feature on our front page. If you want get a hold of him to show off your wares, or to grab some excellent Hackaday stickers, hit him up on Hackaday.io.

Hackaday Links: July 24, 2016

Right now HOPE is dying down, and most of the Hackaday crew will be filtering out of NYC. It was a great weekend. The first weekend in August will be even better. We’re going to DEF CON, we’ll have people at VCF West, and a contingent at EMF Camp. If you’re going to EMF Camp, drop a line here. There will be Hackaday peeps wandering around a field in England, so if you see someone flying the Hackaday or Tindie flag, stop and say hi.

Raspberry Pi’s stuffed into things? Not all of them are terrible. The Apple Extended keyboard is possibly the best keyboard Apple ever produced. It’s mechanical (Alps), the layout is almost completely modern, and they’re actually cheap for something that compares well to a Model M. There’s also enough space inside the plastic to fit a Pi and still have enough room left over for holes for the Ethernet and USB ports. [ezrahilyer] plopped a Pi in this old keyboard, and the results look great. Thanks [Burkistana] for sending this one in.

We’ve been chronicling [Arsenijs] Raspberry Pi project for months now, but this is big news. The Raspberry Pi project has cracked 10k views on Hackaday.io, and is well on track to be the most popular project of all time, on any platform. Congrats, [Arsenijs]; it couldn’t happen to a better project.

A few months ago, [Sébastien] released SLAcer.js, a slicer for resin printers that works in the browser. You can’t test a slicer without a printer, so for the last few months, [Sébastien] has been building his own resin printer. He’s looking for beta testers. If you have experience with resin printers, this could be a very cool (and very cheap) build.

Anyone going to DEF CON? For reasons unknown to me, I’m arriving in Vegas at nine in the morning on Wednesday. This means I have a day to kill in Vegas. I was thinking about a Hackaday meetup at the grave of James T. Kirk on Veridian III. It’s about an hour north of Vegas in the Valley of Fire State Park. Yes, driving out to the middle of the desert in August is a great idea. If anyone likes this idea, leave a note in the comments and I’ll organize something.

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.

Continue reading “The Man Who Didn’t Invent The Personal Computer”

Liberté, Égalité, Fraternité, AZERTY

In the US, we don’t hear much about computing from beyond the Anglosphere. We’ve seen some home computer clones from behind the iron curtain, but getting any information about them is hard. If you find an old keyboard with a QWERTZ layout, or even a few Cyrillic characters, in the States, it’s a rarity. To date, the only French computer on Hackaday is an old Minitel dumb terminal. To help rectify this, [Jeremie Marsin], [Thierry Mazzoleni], and [Jean Paul Mari] from Quebec brought the best of the French computing revolution of the 1980s along to this year’s Vintage Computer Festival East

The American-designed French Victor

The evolution of the reigning champion of this exhibit begins with the Micronique Victor Lambda, a licensed copy of a purely American computer, the Interact Home Computer System. This computer featured a 2 MHz 8080A, 8 or 16 kB of RAM, and was quickly discontinued. The French company Micronique quickly bought the original designs and remarketed the computer in France.

In a few short years, Micronique took this design and turned it into the Hector. This machine featured a 5 MHz Z80, 48 kB of RAM, high resolution graphics (243×231 at four colors) and included BASIC and Forth interpreters.

The Victor and Hector were the best home computers at the time, but for every Commodore or Apple, you need a ZX Spectrum. France’s version of this tiny computer with a terrible keyboard was the Matra Alice 32, a computer with a 1 MHz 6803, 16kB of Ram, and a real 80×25 text mode. The Alice is heavily based on the American TRS-80 MC-10, with a SCART connector and an AZERTY keyboard.


The weirdest computer [Jeremie], [Thierry], and [Jean Paul] brought out? That would be the Excelvision EXL100. The 1980s, for better or worse, were the times of the Z80 and 6502. The EXL100 was running something completely different. This home computer used a TMS7020 CPU from Texas Instruments, a speech synthesizer, and a wireless keyboard. Very strange for the time and relatively inexpensive; in 1984 this computer cost only ₣3190, or about $550 USD.


[Jeremie], [Thierry], and [Jean Paul] had an exhibit that presented the best the Francosphere had to offer to the computing world in the 80s and 90s. We haven’t seen enough early computers from outside the US, so we’re happy to have met these guys at the 11th annual Vintage Computer Festival East.

Building The First Digital Camera

While the official history of the digital camera begins with a Kodak engineer tinkering around with digital electronics in 1975, the first digital camera was actually built a few months prior. At the Vintage Computer Festival East, [William Sudbrink] rebuilt the first digital camera. It’s wasn’t particularly hard, either: it was a project on the cover of Popular Electronics in February, 1975.

Cromemco catalog page for the Cyclops, the first digital camera
Cromemco catalog page for the Cyclops, the first digital camera

[William]’s exhibit, Cromemco Accessories: Cyclops & Dazzler is a demonstration of the greatest graphics cards you could buy for S-100 systems and a very rare, very weird solid-state TV camera. Introduced in the February, 1975 issue of Popular Electronics, the Cyclops was the first digital camera. This wasn’t a device that used a CCD or a normal image sensor. The image sensor in the Cyclops was a 1 kilobit DRAM from MOS, producing a digital image thirty-two pixels square.

The full description, schematic, circuit layout, and theory of operation are laid out in the Popular Electronics article; all [William] had to do was etch a PCB and source the components. The key part – a one kilobit MOS DRAM in a metal can package, carefully decapsulated – had a date code of 1976, but that is the newest component in the rebuild of this classic circuit.

To turn this DRAM into digital camera, the circuit sweeps across the rows and columns of the DRAM array, turning the charge of each cell into an analog output. This isn’t a black or white camera; there’s gray in there, or green if you connect it to an oscilloscope.

This project in Popular Electronics would be manufactured by Cromemco in late 1975 and was released as their first product in January, 1976. The Cromemco was marketed as a digital camera, designed to interface with the MITS Altair 8800 computer, allowing anyone to save digital images to disk. This was the first digital camera invented, and the first digital camera sold to consumers. It’s an amazing piece of history, and very happy [William] was able to piece this together and bring it out to the Vintage Computer Festival this weekend.

VCF East: A Retro Hackathon

We got a banner.
We got a banner.

This weekend is the Vintage Computer Festival East in Wall, New Jersey. Every year is different, but there’s a general plan for each day. On Saturday and Sunday, the exhibits rule the con, the consignment shop is busy, and the keynotes bring down the house. Friday is a little different. This is the day for ‘in the trenches’ talks from the commodore crew, classes on recapping 30-year-old computers, and this year – for the first time – a retro hackathon. It’s basically the same format as any other hackathon, but instead of bringing MacBooks and building something cool, Apple IIs and Commodore 64s were provided. This is the report on the first retro hackathon we’ve ever been to.

The Apple II one-liner SIN graph
The Apple II one-liner SIN graph

First off, no one remembers how to program in BASIC. If you’re looking for a population that should remember the vagaries of the different dialects of BASIC, you would think it would be the people who came out to the middle of Jersey on Friday to talk about old CPUs. Apparently, this is not the case and several people were confused about single and double quotes in PRINT statements. Luckily, a few programming manuals for the C64 and Apple II were available, so everyone could still have fun with PEEKs and POKEs.

If you want to get people programming on some old machines, you need to give them some inspiration. The first half hour of the retro hackathon didn’t see any teams programming. Given this demographics proclivity to say, ‘I can do that better’, I typed a few BASIC one-liners in the C64 (random Truchet tiles in PETSCII) and Apple II (a SIN graph), and the people started pouring in. Yes, they could program something better than a single line of BASIC.

What came of an impromptu retro hackathon? Hangman, in BASIC. No, it didn’t quite work, and there were only three or four possible words hardcoded into the program. Still, text mode graphics are a lost art. The Apple IIc was programmed to make fart noises. The original plan for this project was to program music. What would  have been the winning entry was a line-drawing program on the C64 that looked like the enemy in Qix. That guy wasn’t there during judging. The winner of a $50 credit to the consignment shop was a kid who programmed zero-player Pong on Apple II basic. He bought a Mac Portable (non-backlit) with that prize.

We’ve gone to hackathons, we’ve waded through the sea of MacBooks, and had a Red Bull drip installed. This retro hackathon was completely different, but somehow familiar. No, no one is going to create something new – everything that can be done on these machines in a few hours of BASIC programming has already been done. That’s not the point, though. It’s a geek pride of proving your mettle, putting your money where your mouth is, and doing it in a casual environment where everyone is friendly. This is the first retro hackathon we’ve gone to, and it won’t be the last. We’re going to do this again, once we get an Apple IIc+, a few Commodores, a Speccy, and a few good monitors. We already have the banner, anyway.