Access An 8-bit Atari Through Twitter

October 11, 2020 by 3 Comments

Building a retro computer, or even restoring one, is a great way to understand a lot of the fundamentals of computing. That can take a long time and a lot of energy, though. Luckily, there is a Twitter bot out there that can let you experience an old 8-bit Atari without even needing to spin up an emulator. Just tweet your program to the bot, and it outputs the result.

The bot was built by [Kay Savetz] and accepts programs in five programming languages: Atari BASIC, Turbo-Basic XL, Atari Logo, Atari PILOT, and Atari Assembler/Editor, which was a low-level assembly-type language available on these machines. The bot itself runs on a Raspberry Pi with the Atari 800 emulator, rather than original hardware, presumably because it’s much simpler to get a working network connection on a Pi than on a computer from the 80s. The Pi runs a python script that polls Twitter every two minutes and then hands the code off to the emulator.

[Kay]’s work isn’t limited to just Ataris, though. There’s also an Apple II BASIC bot for all the Apple fans out there that responds to programs written in AppleSoft BASIC. While building your own retro system or emulating one on other hardware is a great exercise, it’s also great that there are tools like these that allow manipulation of retro computers without having to do any of the dirty work ourselves.

Arduino Gets Old PC Booted And Back Into Action

October 11, 2020 by 47 Comments

How many people still have a PS/2 keyboard kicking around in 2020? Admittedly asking such a question of the Hackaday audience is probably cheating (there’s a decent chance one of you will type a comment on one just to prove a point), but even the most pedantic reader has to admit that it’s a long dead standard. So we’re hardly surprised to hear that [Turbaned Engineer] didn’t have one handy when he tried to boot a motherboard so old that he couldn’t access the BIOS with a USB keyboard.

But rather than waiting for an adapter to show up in the mail, he decided to rig up an Arduino Nano to mimic a PS/2 keyboard just long enough for him to navigate the system configuration. Since that basically meant he only needed the arrow keys and Enter, he was able to rig up a handful of momentary buttons to serve as input. We wouldn’t recommend typing out your memoirs with such a spartan board, but it’s certainly good enough to juggle around the order of boot devices.

The fun didn’t stop there, though. [Turbaned Engineer] also had to clean some corrosion and fix a blown resistor on a bank of RAM to drag this old soldier over the finish line. He didn’t have a case handy, so he made a free-form one using the polycarbonate packaging that ICs ship in. The final machine isn’t exactly a sleeper, but it’s good enough to play Super Mario Bros. 3 on the TV.

At the end of the day, the minimal input device [Turbaned Engineer] put together isn’t so far removed from other homebrew keyboards we’ve seen recently. It seems that QMK even has some basic support for the PS/2 interface. Not that it would come up very often, but a “retro” mode might be an interesting addition to your next custom keyboard build.

Modular Rover Platform Rolls On 3D Printed Flexible Tank Tracks

October 11, 2020 by 12 Comments

Master of 3D printed robots, [James Bruton], plans to do some autonomous rover projects in the future, but first, he needed a modular rover platform. Everything is cooler with tank tracks, so he built a rover with flexible interlocking track sections.

The track sections are printed with flexible Ninjaflex filament. Each section has a tab designed to slot through two neighboring pieces. The ends of the tabs stick through on the inside of the track fit into slots on the drive wheel like gear teeth. This prevents the track from slipping under load. The Ninjaflex is almost too flexible, allowing the tracks to stretch and almost climb off the wheels, so [James] plans to experiment with some other materials in the future. The chassis consists of two 2020 T-slot extrusions, which allows convenient mounting of the wheel bogies and other components.

The interlocking track pieces

For initial driving tests [James] fitted two completely overpowered 1500 W brushless motors that he had on hand, which he plans to replace with smaller geared DC motors at a later stage.

A standard RC system is used for control, but it does not offer a simple way to control a skid steer vehicle. To solve this, [James] added an Arduino between the RC receiver and the motor ESC. It converts the PWM throttle and turn signal from the transmitter, and combines is into differential PWM outputs for the two ESCs.

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The Cable Modem To SDR Transformation

October 10, 2020 by 5 Comments

What do you do with an old cable modem in a closet? If you are [stdw] you reverse engineer it and turn it into a software-defined radio. The modem in question was a Motorola MB7220. After looking at a similar project using a different modem, it seemed like it should be doable.

Cracking open the case revealed two likely UART ports, one of which was active. The output from that UART provided a lot of info. The chip was a Broadcom BCM3383 which is a MIPS processor. It had eCos as an operating system. However, the bootloader eventually disables the UART, so there wasn’t much more investigation possible via the serial terminal.

The next step was to dump the flash memory. That required a little solder surgery to prevent the board from starting while the flash chip had power. It appeared that some key credentials and configuration data were present, but they were really backups. After doing a factory reset to remove the backups, the right data was apparent.

After some lengthy exploration, the diagnostic that builds a spectrum display gave up its data. At first, the data was just a small sample of what was really required, but it did show a local FM station as a spectrum. Eventually, the data loss rate was down to about 12% when streaming which is not great, but good enough. You can hear an audio clip of the reception. Not exactly crystal-clear quality, but not bad.

Of course, no one will use this for an FM radio. But it is a fascinating view into how far you can hack into a device like this if you have some skills and patience. There must be something about quarantine that is making people hack old gear, as we just recently saw a similar Netgear hack. Even cheap games aren’t safe.

DIY Braille Embosser Is Really Impressive

October 10, 2020 by 21 Comments

We weren’t surprised to learn that Braille tools are quite expensive. But it’s interesting to hear that there’s another class of tools altogether, and they are very cheap and imprecise. In devising the Braille Embossing Experience, aka BEE, [alatorre] sought to find an open-source middle ground. We think they succeeded marvelously.

Another surprising thing — while handheld embossers do exist, there is no system for filling out an A4 sheet of paper, say, to write a letter.

For Braille to be readable, the characters and lines must be properly spaced, and this requires some kind of moveable type-like device to correctly register the characters onto paper. BEE fills this void as well. The amazing thing is, there’s not much more to it than a marked-up piece of aluminum and some clever 3D printing.

There are two parts to this system — the positioning rail, which includes a landing box for the embosser with six holes in the bottom. The other part is a pair of embossers, one for letters A-M, and another for letters N-Z. To use BEE, just slide the rail to the right and start embossing letters right to left, then flip the paper over when finished.

Need to create something more permanent? Make a Braille PCB.

Heavy Metal Power Bank Uses Tool Batteries

October 10, 2020 by 17 Comments

At one time or another, most of us have seen a gadget for sale and thought we could build something similar for cheaper. Of course, we’re almost always wrong. Not about being able to build it, mind you. But when you add up the cost of the materials, the tool or two you almost inevitably end up buying, and the time spent chasing perfection, you’re lucky if you haven’t doubled the original price.

We’re not sure how much money [Taylor Hay] ended up saving by building his own portable power bank. But we do know it’s a gorgeous piece of hardware that’s certainly built far better than the average consumer gadget. The CNC-cut aluminum side panels look like something pulled out of a tank, and while we know some might balk at the 3D printed internal frame, we’re confident you could use this thing as an impromptu step stool without a problem.

Inside there’s 150 watt 240 VAC inverter, complete with a temperature-controlled fan to keep it cool under load. There are also four USB ports providing 2.1 A each, a standard 12 VDC accessory port, and a LED display that shows battery voltage and current being drawn. Rather than come up with his own battery pack, [Taylor] used a 3D printed interface that accepts an 18 V Milwaukee cordless tool battery. Naturally, the design could be adapted to take another brand’s cells if you were so inclined.

Around these parts, we know that a good project doesn’t have to be cheaper or even more practical than what’s already on the market. There’s an inherent value in building something exactly the way you want it that you simply can’t put a monetary price on.

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Procedural Barcode Synth Is As Simple As Black And White

October 10, 2020 by 3 Comments

We are no stranger to peculiar and wonderful musical instruments here at Hackaday. [James Bruton] has long been fascinated with barcode scanners as an input source for music and now has a procedural barcode-powered synth to add to his growing collection of handmade instruments. We’ve previously covered his barcode guitar, which converts a string of numbers from the PS/2 output to pitches. This meant having a large number of barcodes printed as each pitch required a separate barcode. As you can imagine, this makes for a rather unwieldy and large instrument.

Rather than looking at the textual output of the reader, [James] cracked it open and put it to the oscilloscope. Once inside, he found a good source that outputs a square wave corresponding to the black and white lines that the barcode sees. Since the barcodes [James] is using don’t have the proper start and stop codes, the barcode reader continuously scans.  Normally it would stop the laser to send the text over the USB or PS/2 connection. A simple 5v to 3.3v level shifter feeds that square wave into a Teensy board, which outputs the audio.

A video showcasing a similar technique inspired [James] with this project. The creators of that video have a huge wall of different patterns of black and white lines. [James’s] next stroke of brilliance was to have a small HDMI display to generate the barcodes on the fly. A Raspberry Pi 4 reads in various buttons via GPIO and displays the resulting barcode on the screen. A quick 3d printed shell rounds out the build nicely, keeping things small and compact. All the code and CAD files are up on GitHub.

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