VCF West: Homebrew Lisp Machines And Injection Molded PDPs

Someone walks into the Vintage Computer Festival and asks, ‘what’s new?’. It’s a hilarious joke, but there is some truth to it. At this year’s Vintage Computer Festival West, the exhibit hall wasn’t just filled to the brim with ancient computers from the Before Time. There was new hardware. There was hardware that would give your Apple IIgs even more memory. There was new hardware that perfectly emulated 40-year-old functionality. There’s always something new at the Vintage Computer Festival.

Some of the more interesting projects are just coming off the assembly line. If you want a modern-day Lisp machine, that one won’t be assembled until next week, although there was a working prototype at VCF. If you want the greatest recreation of the most beautiful hardware, VCF has your back. Check out these amazing builds below.

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VCF West: All The Floptical Disks

Nowadays, if you want to transfer a file from one computer to another, you’d just send it over the network. In those rare occasions where that won’t work, a USB thumb drive will do. It wasn’t always this way, and it was much more confusing; back in the day when we had floppy drives. We had floptical drives. A single unlabeled 3.5″ floppy disk could be formatted as 360, 720, or 1440k IBM drive, a 400, 800, or 1440k Macintosh drive, an Apple II volume, or an Amiga, or an Acorn, or a host of other logical formats. That’s just one physical format of a floppy disk, and there are dozens more.

For this year’s VCF West, [Foone], hardware necromancer and collector of rare and esoteric removable storage formats, brought out the goods. He has what is probably the most complete collection of different floppy drive formats on the planet, and they were all out on display this weekend.

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VCF West: Adding A Front Panel To The 6502

When you think about vintage computers from the 1970s, the first thing that should spring to mind are front panels loaded up with switches, LEDs, and if you’re really lucky, a lock with a key. Across all families of CPUs from the ’70s, you’ll find front panel setups for Z80s and 8080s, but strangely not the 6502. That’s not to say blinkenlights and panel switches for 6502-based computers didn’t exist, but they were astonishingly rare.

If something hasn’t been done, that means someone has to do it. [Alexander Pierson] built The Cactus, a  6502-based computer that can be controlled entirely through toggle switches and LEDs.

If you’re wondering why something like this hasn’t been built before, you only have to look at the circuitry of the 6502 CPU. The first versions of this chip were built with an NMOS process, and these first chips included bugs, undefined behavior, and could not be run with a stopped clock signal. These problems were fixed with the next chip spin using a CMOS process (which introduced new bugs), but the CMOS version of the 6502 would retain the contents of its registers with a stopped clock signal.

The specs for the Cactus computer are what you would expect from a homebrew 6502 system. The chip is a WDC 65C02S running at 1MHz, there’s 32k of RAM and a 16k EPROM, dual 6551s give serial access at various baud rates, and there are 16 bits of parallel I/O from a 65C22 VIA. The ROM is loaded up with OSI Basic. The real trick here is the front panel, though. Sixteen toggle switches allow the front panel operator to toggle through the entire address space, and eight flip switches can set any bit in the computer. Other controls include Run, Halt, Step, Examine, and Deposit, as you would expect with any front panel computer.

It’s a fantastic piece of work which I missed seeing at VCF East so I’m really glad [Alexander] made the trip between coasts. Cactus is truly something that hasn’t been done before. Not because it’s impossible, but simply because the state of the art technology from when the 6502 was new didn’t allow it. Now we have the chips, and the only limitation is finding someone willing to put in the work.

This Weekend: The Vintage Computer Festival West

This weekend it’s all going down at the Vintage Computer Museum in Mountain View, California. The Vintage Computer Festival West is happening this weekend

What’s going on this year at VCF West? Far too much. The exhibits include everything from floptical disks, a fully restored and operation PDP-11/45, home computers from the UK and Japan, typewriters converted into teletypes, a disintegrated CPU, and LISP machines. The talks are equally spectacular, with a keynote from [Tim Paterson], the creator of 86-DOS, the basis of MS-DOS. You’ll also hear about PLATO, the Internet before the Internet, PDP-1 demonstrations, and if we’re lucky they’re going to fire up the ancient IBM 1401. There will also be a vintage computer consignment, which is at least as interesting as the exhibits. The consignment is basically a museum, but you can buy the exhibits.

VCF West is happening this weekend at the Computer History Museum in Mountain View, itself a worthy destination for a day trip. For one weekend a year, though, the Computer History Museum is taken over by VCF attendees and becomes the greatest place to learn about this history of computing. They even have one of those Waymo bug cars in their autonomous vehicle exhibit.

All of this is going down this Saturday and Sunday, starting at 9am. Tickets are $20 for one day, $30 for the entire weekend, and yes, that includes admission to the Computer History Museum. Don’t miss out!

2017’s VCF West is Another Beloved Trip Down Memory Lane

This past weekend, another smashing round of the Vintage Computer Festival was held at the Computer History Museum in Mountainview. As always, VCF West gathers the sages and lords of vintage computers onto a common ground to talk old-school hardware. It also draws in a collection of unique artifacts, many of which either still work, have been brought back to life, or have otherwise been reincarnated through a modern means. [Bil Herd] and I dropped in to join the crowd, and I snagged a few pics of some new faces and pieces that have been added to the experience since last year.

[Foone’s] Digital Media Archiving

Up first on our bucket list was [Foone], a librarian of digital media archiving. Outside of VCF, he runs a digital media backup gig to help folks backup their niche, often-failing, disk formats into something more modern. His drive for doing this backup features a special “reread” capability, where the file is actually reread dozens of time to validate that the right information was pulled from it.

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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.

diff_analyzer
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.