Popular Electronics Magazine Archive Online

December 3, 2014 by Elliot Williams 42 Comments

They began publishing Popular Electronics magazine in 1954, and it soon became one of the best-selling DIY electronics magazines. And now you can relive those bygone days of yore by browsing through this archive of PDFs of all back issues from 1954 to 1982.

Reading back through the magazine’s history gives you a good feel for the technological state of the art, at least as far as the DIYer is concerned. In the 1950s and 1960s (and onwards) radio is a big deal. By the 1970s, hi-fi equipment is hot and you get an inkling for the dawn of the digital computer age. Indeed, the archive ends in 1982 when the magazine changed its name to Computers and Electronics magazine.

It’s fun to see how much has changed, but there’s a bunch of useful material in there as well. In particular, each issue has a couple ultra-low-parts-count circuit designs that could certainly find a place in a modern project. For example, a “Touch-Controlled Solid State Switch” in July 1982 (PDF), using a hex inverter chip (CD4049) and a small handful of passive components.

But it’s the historical content that we find most interesting. For instance there is a nice article on the state of the art in computer memory (“The Electronic Mind — How it Remembers”) in August 1956 (PDF).

Have a good time digging through the archives, and if you find something you really like, let us know in the comments.

A Z80 Computer With Switches And Blinkenlights

December 1, 2014 by Brian Benchoff 50 Comments

While most people who build their own computer from chips want the finished product to do something useful, there’s something to be said about a huge bank of switches and a bunch of blinkenlights. They’re incredibly simple – most of the time, you don’t even need RAM – and have a great classic look about them.

[Jim] wanted to build one of these computers and wound up creating a minimal system with switches and blinkenlights. It’s based on the Z80 CPU, has only 256 bytes of RAM, and not much else. Apart from a few extra chips to output data and address lines to LEDs and a few more to read switches, there are only two major chips in this computer.

With the circuit complete, [Jim] laser cut a small enclosure big enough to house his stripboard PCB, the switches and LEDs, and a few buttons to write to an address, perform a soft reset, and cycle the clock. One of the most practical additions to this switch/blinkenlight setup is a hand crank. There’s no crystal inside this computer, and all clock cycles are done manually. Instead of pushing a button hundreds of times to calculate something. [Jim] added a small hand crank that cycles the clock once per revolution. Crazy, but strangely practical.

[Jim] made a demo video of his computer in action, demonstrating how it’s able to calculate the greatest common divisor of two numbers. You can check that video out below.

Continue reading “A Z80 Computer With Switches And Blinkenlights” →

[Glasslinger] Builds Tiny Tubes

November 30, 2014 by Brian Benchoff 30 Comments

In the early days of transistors, RCA and GE were battling against silicon with ever smaller vacuum tubes. These tubes – Nuvistors, Compactrons, and some extremely small JAN triodes were some of the tiniest tubes to ever be created. [glasslinger], YouTube’s expert on DIY valves, is pretty close to beating the tiniest tubes that were ever manufactured. He’s created a miniature diode and triode that are about 1/4″ in diameter and 1″ long.

The most difficult part of making a vacuum tube is getting a perfect glass seal around the pins. For this, [glasslinger] is using very fine tungsten wire and glass beads. A bead is placed around each wire, mounted in a stand, and melted together with a torch.

A diode is simple as far as tubes go, requiring only a filament between two pins. [glasslinger] is just stringing a fine piece of wire between two pins and welding them on with a miniature spot welder. After that, it’s just an issue of melting a 1/4″ glass tube to the base of the tube, putting it under vacuum overnight, and sealing it shut.

Build Your Own Raytracing Minion

November 30, 2014 by Adam Fabio 13 Comments

A canceled project left [Craig] with six Raspberry Pi based devices he calls “Minions”. A minion is a Raspberry Pi model A in a small enclosure with an Adafruit 2.2″ 320×240 SPI LCD. The LCD lives in a lollipop style circular housing above the base. [Craig] has found a use for one of his minions as a desktop raytracer.

The Raspberry Pi is quite capable of running Persistance Of Vision Raytracer, or POV-Ray. POV-Ray started life as an early PC based raytracer. Created as a port of an Amiga program called DKBTrace, which was itself a port of a Unix raytracer, POV-Ray first was released in 1987. For the uninitiated, raytracers like POV-Ray literally trace rays from a light source to an image plane. As one would imagine, the Raspberry Pi’s little ARM processor would take quite a bit of time to raytrace a high resolution image. However, when targeting a 320×240 LCD, it’s not half bad.

[Craig’s] minion is running his own software which he calls ArtRays. Based upon a setup file, ArtRays can render images from several sources, including the internet via a WiFi dongle, or a local SD card. Rather than walk through the setup and software install, [Craig] has provided a link to download a full SD card image to build your own Minion. It might be worth experimenting on your own first though, rather than killing his server with a 1GB download.

We’re glad [Craig] has found use for one of his minions, now we have to see what he’s done with the other five!

The Zork Virtual Machine Implemented In Hardware

November 29, 2014 by Brian Benchoff 10 Comments

Zork, Hitchhiker’s Guide to the Galaxy, and all the other Infocom text adventures are much more clever than the appear at first glance. They actually run on a virtual machine, with all the code for the game files squirreled away in the Z-machine format. This is great if you’re writing a game for a dozen platforms; once you have an interpreter running on one system, the entire library of games can be shipped out the door.

While the Z-machine has been ported to all the retrocomputers you can imagine and a few different brands of microcontrollers, no one has yet implemented the Z-machine in hardware. There’s a reason for this: it’s crazy. Nevertheless, [Charlie] managed to implement the Z-machine in an FPGA, using only a few extra commands for driving a display.

The circuit is constructed with a $10 eBay special FPGA, the Cyclone II EP2C5. Other than that, it’s just some Flash, some RAM, a display, and a whole lot of wire. The standard Z-machine spec is followed, version 3 specifically, meaning this text adventure on a chip can run nearly every Infocom game ever written. The most popular ones, at least.

This isn’t [Charlie]’s first time in the ring with the Infocom Z-machine. He ported the Z-machine to a freakin’ pen a few years ago.

You can check out [Charlie]’s video demo below. Because there was a bit of extra space in the FPGA, [Charlie] managed to put a Mandelbrot implementation and Space Invaders in as an easter egg.

Continue reading “The Zork Virtual Machine Implemented In Hardware” →

ArTICam Interfaces Game Boy Camera With TI Calculators

November 29, 2014 by Adam Fabio 4 Comments

[Christopher Mitchell] has given Texas Instruments calculators the ability to capture images through a Game Boy Camera with ArTICam. First introduced in 1998, The Game Boy Camera was one of the first low-cost digital cameras available to consumers. Since then it has found its way into quite a few projects, including this early Atmel AT90 based hack, and this Morse code transceiver.

TI calculators don’t include a Game Boy cartridge slot, so [Christopher] used an Arduino Uno to interface the two. He built upon the Arduino-TI Calculator Linking (ArTICL) Library to create ArTICam. Getting the Arduino to talk with the Game Boy Camera’s M64282FP image sensor turned out to be easy, as there already are code examples available. The interface between the camera sensor and the Arduino is simple enough. 6 digital lines for an oddball serial interface, one analog sense line, power and ground. [Christopher] used a shield to solder everything up, but says you can easily get away with wiring directly the Arduino Uno’s I/O pins. The system is compatible with the TI-83 Plus and TI-84 Plus family of calculators. Grabbing an image is as simple as calling GetCalc(Pic1) from your calculator program.

So, If you have an old calculator lying around, give it a try to enjoy some 128×123-pixel grayscale goodness!

[Fran]’s New Project: The DSKY

November 28, 2014 by Brian Benchoff 29 Comments

[Fran] has already made a name for herself in some retro cool historical aviation and computer circles by tearing down a flight-ready spare of a Saturn V launch vehicle digital computer, the computer that was responsible for getting all flights to the moon into low earth orbit. Now she’s ready for another project, and again, this is something that hasn’t been done in 40 years. She’s building a DSKY, the control panel for the Apollo Guidance Computer

The Apollo Guidance Computer is a well-documented piece of computing history, with homebrew versions all over the web. The DSKY is only one small part of the AGC, but it is by far the most famous module. Being the only user interface for the AGC, it’s the only part of the AGC that gets all the screen time in Apollo 13, the travesty on BluRay that was Apollo 18, and is the only device that bears any physical resemblance to its real-life counterpart in a number of AGC simulators.

That’s not to say DSKY builds haven’t been attempted before; there are a few out there using LEDs and off-the-shelf buttons for the build, but the DSKY from the mid-60s is much, much cooler than a bunch of LEDs and light pipes. The eery green numbers are actually EL displays. Guess how those displays are controlled? Relays. It’s a masterpiece of technology, made even more impressive in that the folks at MIT who built the thing didn’t have anything better to build the display with.

Because of her deconstruction efforts with the Saturn V LVDC, [Fran] was invited down to the National Air and Space museum in the middle of Washington DC. There, she saw everyones favorite ugliest spacecraft, the Apollo LEM, along with an incredible assortment of paraphernalia from aviation history. The Wright Flyer – yes, the original one – is hanging from the ceiling next to the Spirit of St. Louis, and X-15 rocket plane, right above the command module Columbia from Apollo 11. Copies of probes currently rolling over Mars are on display, and you can walk through a training model of Skylab. If you’ve never been, spend half a day there, then take the metro out to the Udvar-Hazy center, where you’ll find all the stuff they couldn’t fit in the downtown collection like a Space Shuttle and a Concorde.

This is only the first part of [Fran]’s vlog documenting the construction of a copy of the DSKY, and we haven’t even seen the inner guts of the most famous part of the AGC yet. She’s been working on this for a while now, and there’s no doubt she’ll finish the job and come up with the best replica of a DSKY ever.