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.

Radio Shack Returns

In February 2015, Radio Shack–an icon in American malls and towns–filed for bankruptcy. You could say a lot of critical things about Radio Shack, but in many parts of the country, it was the only place you were going to go find electronic components on short notice. A lot of people of a certain age got their exposure to electronics via Radio Shack kits and parts.

Radio Shack did close a lot of stores. In fact, from 4,000 stores they are down to about 1,700. A New York hedge fund named Standard General bought all the Radio Shack assets and formed a new company (also called, oddly enough, Radio Shack). They just named [Dene Rogers] as CEO. He’s a veteran at retail sales, having been with Target in Australia and Sears in Canada.

Continue reading “Radio Shack Returns”

Hackaday Links: February 8, 2015

[CNLohr] is famous for his extremely strange projects, including something that does something with Minecraft that even he can’t describe. Over the years, he’s built up a vast collection of projects that have been both incredible fails and successes. Here’s a video tour of all those projects.

For this week’s edition “Kickstarter is going insane”, you only need to look at the title of the campaign: Tesla Coils for North Korea.

Last week, a few slow scan TV signals were received from the International Space Station. Here’s the reddit thread.

The worst thing about using an Arduino in a semi-professional environment is the IDE. Here’s cuwire, a better IDE.

Wanna see something insane? How about an SSH library written in x64 assembly?

Radio Shack is in its death throes, and since you haven’t gone in the last few years, you might as well head out one last time and pick up some items on clearance. Here’s the list of store closings (PDF) and all 1,784 stores slated to be closed plotted on Google Maps.

I’ve come to bury Radio Shack, Not praise it.

This is a post that has been a long time coming. Today, Radio Shack, the store that has been everything from an excellent introduction to electronics and computers to a store that sells cell phones, cell phone accessories, and cell phone plans has declared bankruptcy.

To anyone, this should not be news. For the last decade, the public perception of Radio Shack was one of a shell of its former self. In 2007, The Onion famously published Even CEO Can’t Figure Out How RadioShack Still In Business, an article that like most of The Onion’s work, is a sand dune of grains of truth.

In recent years, Radio Shack has made attempts to appeal to the demographic that holds the ‘shack in such high regard. Just four short years ago, Radio Shack made an appeal to this community and asked for suggestions for what people would actually buy at Radio Shack. The answers ranged from Arduinos and larger component selections to Parallax Propellers. Even with this renewed focus on DIY, repair, electronic tinkering, and even in-house cellphone repair shops in some select locations, this was not enough.

This was a make or break year for Radio Shack. Last fall, Standard General, a hedge fund with an amazing name, attempted to refinance Radio Shack’s debt with specific revenue benchmarks set for the holiday season. These benchmarks were not met, and now Radio Shack has filed for bankruptcy protection after reaching a deal to sell nearly 2,500 stores. Radio Shack now has about 5,000 stores in the U.S.. Half of them will close, and as many as 1,700 will be operated by Sprint. The future of Radio Shack was a cell phone store, it seems.

Right now, there are rumors of Radio Shack employees ‘released from service’, with mass closings of stores very, very soon.

There has always been a love-hate relationship with Radio Shack with the DIY and tinkerer community. It was everything from many programmer’s first introduction to computers, the only place in town you could buy [Forrest Mims]’ excellent books, to a horrible place to work, and an odd store where you need a phone number to buy batteries.

This is not a eulogy; Radio Shack isn’t quite dead just yet, and eulogies are reserved for the loved ones in our lives. Radio Shack is neither. We all have a rich history with Radio Shack, and next time you’re buying some resistors on Mouser or Digikey, just remember we’re living in a different world now.

Thermal Printer Brain Transplant is Two Hacks in One

You know how sometimes you just can’t resist collecting old hardware, so you promise yourself that you will get around to working on it some day? [Danny] actually followed through on one of those promises after discovering an old Radio Shack TRS-80 TP-10 thermal printer in one of his boxes of old gear. It looks similar to a receipt printer you might see printing receipts at any brick and mortar store today. The original printer worked well enough, but [Danny] wasn’t satisfied with its 32 character per line limitation. He also wanted to be able to print more complex graphics. To accomplish this goal, he realized he was going to have to give this printer a brain transplant.

First, [Danny] wanted to find new paper for the printer. He only had one half of a roll left and it was 30 years old. He quickly realized that he could buy thermal paper for fax machines, but it would be too wide at 8.5 inches. Luckily, he was able to use a neighbor’s saw to cut the paper down to the right size. After a test run, he knew he was in business. The new fax paper actually looked better than the old stuff.

The next step was to figure out exactly how this printer works. If he was going to replace the CPU, he was going to need to know exactly how it functioned. He started by looking at the PCB to determine the various primary functions of the printer. He needed to know which functions were controlled by which CPU pins. After some Google-Fu, [Danny] was able to find the original manual for the printer. He was lucky in that the manual contained the schematic for the circuit.

Once he knew how everything was hooked up, [Danny] realized that he would need to learn how the CPU controlled all of the various functions. A logic analyzer would make his work much easier, but he didn’t happen to have one lying around. [Danny] he did what any skilled hacker would do. He built his own!

He built the analyzer around an ATMega664. It can sample eight signals every three microseconds. He claims it will fill its 64k of memory in about one fifth of a second. He got his new analyzer hooked up to the printer and then got to work coding his own logic visualization software. This visualization would provide him with a window to the inner workings of the circuit.

Now that he was able to see exactly how the printer functioned, [Danny] knew he would be able to code new software into a bigger and badder CPU. He chose to use another ATMega microcontroller. After a fair bit of trial and error, [Danny] ended up with working firmware. The new firmware can print up to 80 characters per line, which is more than double the original amount. It is also capable of printing simple black and white graphics.

[Danny] has published the source code and schematics for all of his circuits and utilities. You can find them at the bottom of his project page. Also, be sure to catch the demonstration video below. Continue reading “Thermal Printer Brain Transplant is Two Hacks in One”