Hackaday Links: October 8, 2017

On the top of the popcorn pile for this weekend is an ambiguous tweet from Adafruit that was offered without comment or commentary. [Lady Ada] is holding some sort of fancy incorporation papers for Radio Shack. The smart money is that Adafruit just bought these at the Radio Shack auction a month or so ago. The speculation is that Adafruit just bought Radio Shack, or at least the trademarks and other legal ephemera. Either one is cool, but holy crap please bring back the retro 80s branding.

A Rubik’s Cube is a fantastic mechanical puzzle, and if you’ve never taken one apart, oh boy are you in for a treat. Here’s an RGB LED Rubick’s Cube with not enough detail as to how each square is getting powered. Here’s an open challenge for anyone: build an RGB LED Rubick’s Cube, and Open Source the design.

Last weekend, the front fell off the engine of an Air France A380 flying over Greenland. As with all aircraft incidents, someone has to find the missing bits. It only took a week to find a mangled cowling on an ice sheet. This is incredibly impressive; if you want a comparison to another accident, it took three months to find the fan disk for UA 232 in an Iowa cornfield.

Poorly thought out Kickstarters don’t grab our attention like they used to, but this is an exception. The Aire is a mashup of one of those voice-activated home assistants (Alexa, whatever the Google one is named…) and a drone. The drone half of the build is marginally interesting as a ducted fan coaxial thingy, and building your own home assistant isn’t that hard with the right mics and a Raspberry Pi. The idea is actually solid — manufacturing is another story, though. It appears no one thought about how annoying it would be to have a helicopter following them around their house, or if the mics would actually be able to hear anyone over beating props. Here’s the kicker: this project was successfully funded. People want to buy this. A fool and his or her money…

Processing is cool, although we’re old skool and still reppin’ Max/MSP. It looks like the first annual Processing Community Day is coming up soon. The Processing Community Day will be at the MIT Media Lab on October 21st, with talks from the headliners of the Processing community.

Maker Faire NYC was two weekends ago, the TCT show in Birmingham was last week, and Open Hardware Summit was in Denver this weekend. Poor [Prusa] was at all of them, racking up the miles. He did, however, get to ride [James from XRobots.co.uk]’s electric longboard. There’s some great videos from [James] right here and here.

Speaking of Open Hardware Summit, there was a field trip to Sparkfun and Lulzbot this Friday. The highlight? The biggest botfarm in the states, and probably the second largest in the world. That’s 155 printers, all in their own enclosures, in a room that’s kept at 80° F. They’re printing ABS. Control of the printers is through a BeagleBone running Octoprint. These ‘Bones and Octoprint only control one printer each, and there is no software layer ‘above’ the Octoprint instances for managing multiple printers simultaneously. That probably means the software to manage a botfarm doesn’t exist. There have been attempts, though, but nothing in production. A glove thrown down?

Pac Man On The Colour Computer 3

The 1980s were the heyday of the venerable Z80, a processor that found its way into innumerable home computers, industrial systems, and yes — arcade machines. However, not everyone had a Z80 based machine at home, and so sometimes porting is required. [Glen] is tackling this with a port of Pac Man to the Radio Shack Colour Computer 3.

The key to any good arcade port is authenticity – the game should feel as identical to the real thing as possible. The Atari 2600 port got this famously wrong. Porting to the Colour Computer 3 is easier in theory – with more RAM, a Motorola 6809 CPU running at a higher clock rate, and a more powerful graphics subsystem, fewer compromises need to be made to get the game to run at a playable speed.

The way [Glen] tackled the port is quite handy. [Glen] built a utility that would scrape a disassembled version of the original Pac Man Z80 code, look up the equivalent 6809 CPU instruction, and replace it, while placing the original Z80 code to the side as a comment. Having the original code sitting next to the ported instructions makes debugging much easier.

Level 256 as seen in [Glen]’s port.
There was plenty of hand tweaking to be done, and special effort was made to make sure all the data the original code was looking for was accessible at the same addresses as before. There was also a lot of work involved in creating a sprite engine that would reliably display the game video at a playable frame rate.

Overall, the port is highly faithful to the original, with the game code being identical at the CPU level. [Glen] reports that the same patterns used on the arcade machine can be used to complete the mazes on the Colour Computer 3 version, and it faithfully recreates the Level 256 bug as well. It’s an impressive piece of work to create such an authentic port on a home computer from 1986.

For another classic port, but with the temporal vectors flipped, check out Portal 2 on the Apple II.


A Goldmine Of Radio Shack Goodies Is Up For Auction

Where did you buy the parts for your first electronic project? That’s a question likely to prompt a misty-eyed orgy of reminiscences from many Hackaday readers, if ever we have heard one. The chances are that if you are from North America or substantial parts of the English-speaking world, you bought them from a store that was part of the Radio Shack empire. These modestly sized stores in your local mall or shopping centre carried a unique mix of consumer electronics, CB radio, computers, and electronic components, and particularly in the days before the World Wide Web were one of very few places in which an experimenter could buy such parts over the counter.

Sadly for fans of retail electronic component shopping, the company behind the Radio Shack stores faltered in the face of its new online competition over later years of the last decade, finally reaching bankruptcy in 2015. Gone are all but a few independently owned stores, and the brand survives as an online electronics retailer.

The glory days of Radio Shack may be long gone, but its remaining parts are still capable of turning up a few surprises. As part of the company’s archives they had retained a huge trove of Radio Shack products and memorabilia, and these have been put up for sale in an online auction.

There is such a range if items for sale that if you are like us you will probably find yourself browsing the listings for quite a while. Some of it is the paraphernalia of a corporate head-office, such as framed artwork, corporate logos, or strangely, portraits of [George W. Bush], but the bulk of the collection will be of more interest. There are catalogues galore from much of the company’s history, items from many of its promotions over the years including its ventures into sporting sponsorship, and numerous examples of Radio Shack products. You will find most of the computers, including a significant number of TRS-80s and accessories, tube-based radios and equipment from the 1950s, as well as cardboard boxes stuffed with more recent Realistic-branded items. There are even a few retail technology dead ends to be found, such as a box of :CueCat barcode readers that they evidently couldn’t give away back in the dotcom boom.

If you are interested in any of the Radio Shack lots, you have until the 3rd of July to snap up your personal piece of retail electronic history. Meanwhile if you are interested in the events that led to this moment, you can read our coverage of the retail chain’s demise.

Thanks [Mark Scott] for the tip.

Forrest Mims, Radio Shack, and the Notebooks that Launched a Thousand Careers

There was a time when Radio Shack offered an incredible variety of supplies for the electronics hobbyist. In the back of each store, past the displays of Realistic 8-track players, Minimus-7 speakers, Patrolman scanners, and just beyond the battery bin where you could cash in your “Battery of the Month Club” card for a fresh, free 9-volt battery, lay the holy of holies — the parts. Perfboard panels on hinges held pegs with cards of resistors for 49 cents, blister packs of 2N2222 transistors and electrolytic capacitors, and everything else you needed to get your project going. It was a treasure trove to a budding hardware hobbyist.

But over on the side, invariably near the parts, was a rack of books for sale, mostly under the Archer brand. 12-year old me only had Christmas and birthday money to spend, and what I could beg from my parents, so I tended to buy books — I figured I needed to learn before I started blowing money on parts. And like many of that vintage, one of the first books I picked up was the Engineer’s Notebook by Forrest M. Mims III.

Wish I could find my original copy from 1979. This one is on Amazon.
Wish I could find my original copy from 1979. I just bought this one from Amazon.

Many years rolled by, and my trusty and shop-worn first edition of Mims’ book, with my marginal notes and more than one soldering iron burn scarring its pulp pages, has long since gone missing. I learned so much from that book, and as I used it to plan my Next Big Project I’d often wonder how the book came about. Those of you that have seen the book and any of its sequels, like the Mini-notebook Series, will no doubt remember the style of the book. Printed on subdued graph paper with simple line drawings and schematics, the accompanying text did not appear to be typeset, but rather hand lettered. Each page was a work of technical beauty that served as an inspiration as I filled my own graph-paper notebooks with page after page of circuits I would find neither the time nor money to build.

I always wondered about those books and how they came about. It was a pretty astute marketing decision by Radio Shack to publish them and feature them so prominently near the parts — sort of makes the string of poor business decisions that led to the greatly diminished “RadioShack” stores of today all the more puzzling. Luckily, Forrest Mims recently did an AMA on reddit, and he answered a lot of questions regarding how these books came about. The full AMA is worth a read, but here’s the short story of those classics of pulp non-fiction.

Continue reading “Forrest Mims, Radio Shack, and the Notebooks that Launched a Thousand Careers”

Hollow State Receiver

[Netzener] received a Radio Shack P-Box one tube receiver as a gift. However, at the time, his construction skills were not up to the task and he never completed the project. Years later, he did complete a version of it with a few modern parts substitutions. The radio worked, but he was disappointed in its performance. Turns out, the original Radio Shack kit didn’t work so well, either. So [Netzener] did a redesign using some some old books from the 1920’s. The resulting radio–using parts you can easily buy today–works much better than the original design.

The most expensive part of the build was a 22.5V battery, which cost about $25. However, you can get away with using three 9V batteries in series if you want to save some money. The battery provides the plate voltage for the 1T4 vacuum tube. A more conventional AA battery drives the tube’s filament. Continue reading “Hollow State Receiver”

1980s Toy Robot Arm Converted To Steam And Other Explorations

We were doing our daily harvest of YouTube for fresh hacks when we stumbled on a video that eventually led us to this conversion of a 1980s Armatron robot to steam power.

The video in question was of [The 8-bit Guy] doing a small restoration of a 1984 Radio Shack Armatron toy. Expecting a mess of wiring we were absolutely surprised to discover that the internals of the arm were all mechanical with only a single electric motor. Perhaps the motors were more expensive back then?

The resemblance is uncanny.
The resemblance is uncanny.

The arm is driven by a Sarlacc Pit of planetary gears. These in turn are driven by a clever synchronized transmission. It’s very, very cool. We, admittedly, fell down the google rabbit hole. There are some great pictures of the internals here. Whoever designed this was very clever.

The robot arm can do full 360 rotations at every joint that supports it without slip rings. The copper shafts were also interesting. It’s a sort of history lesson on the prices of metal and components at the time.

Regardless, the single motor drive was what attracted [crabfu], ten entire years ago, to attach a steam engine to the device. A quick cut through the side of the case, a tiny chain drive, and a Jensen steam engine was all it took to get the toy converted over. Potato quality video after the break.

Continue reading “1980s Toy Robot Arm Converted To Steam And Other Explorations”

Metalized Gift Wrap Saves A Classic Keyboard

What do you do when you decide that running CP/M on a Commodore 128 with a 5.25″ drive “Isn’t CP/M enough”? If you are [Chris Osborn], you reach for your trusty TRS-80 Model II, with its much more CP/M-appropriate 8″ drive.

There was one small snag with the TRS-80 though, its keyboard didn’t work. It’s a capacitive device, meaning that instead of each key activating a switch, it contains a capacitive sensor activated by a piece of aluminized Mylar film on a piece of foam. Nearly four decades of decay had left the foam in [Chris]’s example sadly deflated, leaving the keys unable to perform. Not a problem, he cast around for modern alternatives and crafted replacements from a combination of foam weather strip and metalized gift wrap.

Care had to be taken to ensure that the non-metalized side of the gift wrap faced the capacitive sensor pads, and that the weather strip used had the right thickness to adequately fill the gap. But the result was a keyboard that worked, and for a lot less outlay and effort than he’d expected. We would guess that this will be a very useful technique for owners of other period machines with similar keyboards.

What is CP/M, I hear you ask? Before there was Linux, Windows, and MacOS, there was DOS, and before DOS, there was CP/M. In the 1970s this was the go-to desktop operating system, running on machines powered by Intel’s 8080 and its derivatives like the Zilog Z80 in the TRS-80. When IBM needed an OS for their new PC they initially courted CP/M creators Digital Research, but eventually they hired a small software company called Microsoft instead, and the rest is history. Digital Research continued producing CP/M and its derivatives, as well as an MS-DOS clone and the GEM GUI that may be familiar to Atari ST owners, but were eventually absorbed into Novell in the 1990s.

We’ve featured a few capacitive keyboards here at Hackaday before, including this similar repair to a Compaq from the 1980s, and this look at a classic IBM terminal keyboard.