New Hard Drives for Old Computers

After a certain age, computers start to show signs that they might need to be replaced or upgraded. After even more time, it starts getting hard to find parts to replace the failing components. And, as the sands slip through the hourglass, the standards used to design and build the computer start going obsolete. That’s the situation that [Drygol] found himself in when he was asked to build a SD-card hard drive for an Atari.

The 8-bit Atari in question was a fixture of home computing in the 80s. In fact, if you weren’t on the Commodore train, it’s likely that your computer of choice was an Atari. For the nostalgic among us, a new hard drive for these pieces of history is a great way to relive some of the past. Working off of information from the SIO2SD Wiki page, [Drygol] used the toner transfer method to build a PCB, 3D printed a case, and got to work on his decades-old computer.

Resurrecting old hardware is a great way to get into retrocomputing. Old protocols and standards are worth investigating because they’re from a time where programmers had to make every bit count, and there are some gems of genius hidden everywhere. Whether you’re reworking SIO from an old Atari, or building a disk emulator for an Apple ][, there are lots of options.

The Newest Graphing Calculator Game

Certainly everyone remembers passing time in a boring high school class playing games on a graphing calculator. Whether it was a Mario-esque game, Tetris, or BlockDude, there are plenty of games out there for pretty much all of the graphing calculators that exist. [Christopher], [Tim], and their colleagues from Cemetech took their calculator game a little bit farther than we did, and built something that’ll almost surely disrupt whatever class you’re attempting to pay attention in: They built a graphing calculator whac-a-mole game.

This game isn’t the standard whac-a-mole game, though, and it isn’t played on the calculator’s screen. Instead of phyiscal “moles” the game uses LEDs and light sensors enclosed in a box to emulate the function of the moles. In order to whack a mole, the player only needs to interrupt the light beam which can be done with any physical object. The team made extensive use of the ArTICL library which allows graphing calculators to interface with microcontrollers like the MSP432 that they used, and drove the whole thing with a classic TI-84.

This project is a fun way to show what can be done with a graphing calculator and embedded electronics, and it was a big hit at this past year’s World Maker Faire. Calculators are versatile in other ways as well. We’ve seen them built with open hardware and free software, And we’ve even seen them get their own Wi-Fi.

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Scratching Vinyl Straddles Physical and Digital Realms

The life of a modern DJ is hard. [Gergely] loves his apps, but the MIDI controller that works with the app feels wrong when he’s scratching, and the best physical interfaces for scratching only work with their dedicated machines. [Gergely]’s blog documents his adventures in building an interface to drive his iPad apps from a physical turntable. But be warned, there’s a lot here and your best bet is to start at the beginning of the blog (scroll down) and work your way up. Or just let us guide you through it.

In one of his earliest posts he lays out his ideal solution: a black box that interprets time-code vinyl records and emulates the MIDI output of the sub-par MIDI controller. Sounds easy, right? [Gergely] gets the MIDI side working fairly early on, because it’s comparatively simple to sniff USB traffic and emulate it. So now he’s got control over the MIDI-driven app, and the hard part of interfacing with the real world began.

After experimenting a lot with timecode vinyl, [Gergely] gives up on that and looks for an easier alternative. He also considers using an optical mouse, but that turns out to be a dead-end as well. Finally, [Gergely] settled on using a Tascam TT-M1, which is basically an optical encoder that sits on top of the record, and that makes the microcontroller’s job a lot easier. You can see the result in the video below the break.

And then in a surprise ending worthy of M. Night (“I see dead people”) Shyamalan  he pulls timecode vinyl out of the grave, builds up a small hardware translator, and gets his original plan working. But we have the feeling that he’s not done yet: he also made a 3D printed optical-mouse holder.

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Tracking eye movement by measuring electrons in the eye

[Luis Cruz] is a Honduran High School student, and he built an amazing electrooculography system, and the writeup (PDF warning) of the project is one of the best we’ve seen.

[Luis] goes through the theory of the electrooculogram – the human eye is polarized from front to back because of a negative charge in the nerve endings in the retina. Because of this minute difference in charge, a user’s gaze can be tracked by electrodes attached to the skin around the eye. After connecting eye electrodes to opamps and a microcontroller, [Luis] imported the data with a Python script and wrote an “eyeboard” application to enable text input using only eye movement. The original goal of the project was to build an interface for severely disabled people, but [Luis] sees applications for sleep research and gathering marketing data.

We covered [Luis]’ homebrew 8-bit console last year, and he’s now controlling his Pong clone with his eye-tracking device. We’re reminded of a similar system developed by Atari, but [Luis]’ system uses a method that won’t give the user a headache after 15 minutes.

Check out [Luis] going through the capabilities of his interface after the break. Continue reading “Tracking eye movement by measuring electrons in the eye”

So you want to make a Command Line Interface

[Keba] not only asked, but also sent us an email as follows.

“Can you make a basic guide to designing a good Command Line User Interface?”

Wouldn’t you know the luck, I’m currently working on a Command Line type interface for a project of mine. While after the jump I’ll be walking through my explanation, it should be noted that the other replies to are also great suggestions.

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Texas Instruments watch claims it’s a computer mouse

[Jack Toole] and his team [Aaron King] and [Libo He] sent in their computer interface dubbed the Chronos Flying Mouse. The video above explains the concept very thoroughly, but we’ll reiterate some of the highlights here. The project uses a Chronos EZ430 with its accelerometers to wirelessly transmit delta positions of the user’s wrist. Add a little open source software and you have a regular PC mouse, a video game joystick, a game wheel, and a few other different devices in one. We just love the suave feeling of snapping to click.

Nexus one gets Linux

Considering how hackable the Nexus One is already, we can only imagine a whole new host of interesting things thanks to Ubuntu running on the device. [Max Lee] set his heart out on getting not just Ubuntu on the Nexus One, but also Debian, and he wrote a perfect install guide to help out those wanting to give it a shot.

He cheated a little bit by having Ubuntu run in the background while the X11 interface is simply VNCed, but he still did an awesome job with plenty of pictures and details to help you achieve Ubuntu on your Nexus One.