Visualizing Magnetic Memory With Core 64

For the vast majority of us, computer memory is a somewhat abstract idea. Whether you’re declaring a variable in Python or setting a register in Verilog, the data goes — somewhere — and the rest really isn’t your problem. You may have deliberately chosen the exact address to write to, but its not like you can glance at a stick of RAM and see the data. And you almost certainly can’t rewrite it by hand. (If you can do either of those things, let us know.)

These limitations must have bothered [Andy Geppert], because he set out to bring computer memory into the tangible (or at least, visible) world with his interactive memory badge Core 64. [Andy] has gone through a few different iterations, but essentially Core 64 is an 8×8 grid of woven core memory, which stores each bit via magnetic polarization, with a field of LEDs behind it that allow you to visualize what’s stored. The real beauty of this setup is that it it can be used to display 64 pixel graphics. Better yet — a bit can be rewritten by introducing a magnetic field at the wire junction. In other words, throw a magnet on a stick into the mix and you have yourself a tiny drawing tablet!

This isn’t the first time we’ve seen cool experiments with core memory, and not even the first time we’ve seen [Andy] use it to make something awesome, but it really illuminates how the technology works. Being able to not only see memory being written but to manually write to it makes it all so much realer, somehow.

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2020: Everything Is Virtual

It’s like the dystopian future arrived out of the blue. From one year to the next we went from holing up in overly air-conditioned hotel ballrooms and actually meeting our fellow meatbags in the flesh, to huddling in our pods and staring at the screens. I’m looking for the taps to hook me in to the Matrix at this point.

But if you haven’t yet received your flying car or your daily Soma ration, you can still take comfort in one thing: all of the hacker conferences are streaming live, as if it were some fantastic cyber-future! In fact, as we type this, someone is telling you how to print your way to free drinks on USAir flights as part of HOPE’s offering, but the talks will continue for the next few days. (Go straight to live stream one.)

If retrocomputing is more your thing, Saturday marks the start of the virtual Vintage Computer Festival West of which Hackaday is a proud sponsor. (Here’s the schedule.)

And next weekend is DEF CON in Safe Mode with Networking. While we can totally imagine how the talks and demo sessions will work, the Villages, informal talks and hack-togethers based on a common theme, will be a real test of distributed conferencing.

OK, I’ll admit it: I really miss getting together with folks and having the truly random conversations that pre-scripted teleconferences just don’t seem to facilitate. Lobbycon suffers in lockdown. But if you’ve never been to any of these events, and you just want a taste of the talks and presentations at least, now’s your chance to get in for free. And if you like what you see, and if the virus lets us, we’ll see you in person next summer!

Saturday: Vintage Computer Festival West

The Vintage Computer Festival West is an annual gathering to celebrate the awesome hardware that ushered in the Information Age. Normally held at the Computer History Museum in Mountain View, California, this year VCF West is happening virtually and it all starts on Saturday!

The lineup of talks looks great, covering everything from operating an Apollo DSKY display panel and how to recover magnetic tape to ENIAC technical manual bugs and the genesis of the 6502. That last one is presented by Bill Mensch who was on the team that created the 6502 in the first place. He’ll be joined by Hackaday’s own Bil Herd (himself a celebrated Commodore and MOS alum) and Eric Schlaepfer (you may remember his Monster 6502 project). You may not be able to wander the exhibits and play with the vintage hardware this year, but you can hear from a lot of people who have spent years learning the hacks and quirks that made these systems tick.

Hacakaday is proud to once again sponsor VCF West. You don’t need a ticket, the conference will live stream on their YouTube channel for all who are interested. We’ve embedded the live stream below, as well as the awesome poster at that Joe Kim produced for display at the festival.

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Vintage Computer Festival West Is Almost Here

If you’ve got an interest in technology, a penchant for that particular shade of yellowed plastic, and happen to be located in the California area, then we’ve got the event for you. The Vintage Computer Festival West is happening this weekend, August 3rd and 4th, at the Computer History Museum in Mountain View, California.

The Vintage Computer Festival offers a truly unique experience for anyone with a passion for all the silicon that’s come before. Where else could you sit in on a roundtable of early Apple employees discussing the bevy of authentic ultra-rare Apple I computers that will be on display, or get up close and personal with a restored Apollo Guidance Computer? If you really want to dive in on the deep end, Hackaday’s own Bill Herd will be in attendance giving his lecture about the effects of heat and time on the internal components of decades-old pieces of hardware.

Still skeptical? Perhaps you’ll get a kick out of the exhibit that celebrates more than two decades of Quake by hosting a LAN game where the classic game is running on less common platforms like the RS/6000 series or the Sun Ulta. If you’re interested in seeing modern reconstructions of classic technology, there will be plenty of that on display as well. Eric Schlaepfer will be showing off his transistor-scale replica of the iconic 6502 microprocessor, and you won’t want to miss the Cactus in all its rainbow colored toggle switch and blinkenlight glory.

Of course, if you’re in the market for your very own piece of computing history, there’s no better place to be. The consignment area gives showgoers a chance to buy and sell all manners of vintage and unique hardware, harking back to the days where the best way to get your hands on a computer (or the parts to build one) was by attending a dedicated event. Plus, no shipping fees!

Put simply, there really is something for everyone at the Vintage Computer Festival. Even if you weren’t around to experience Apple II or Commodore 64 in their prime, these events are a rare opportunity to learn about the early days of a technology that today we all take for granted. Have you ever wondered how programs were entered into those early computers with nothing more than a bank of toggle switches and an array of LEDs? One of the passionate exhibitors at VCF will be more than happy to walk you through the process.

At the end of the day, preserving this technology and sharing it with future generations is really what it’s all about. Just as in previous years, Hackaday is proud to sponsor the Vintage Computer Festival and further their goal of ensuring this incredible shared heritage isn’t lost.

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.