Roundup: Retro Computers In Your Browser

September 28, 2015 by Al Williams 51 Comments

There are two things that keep me from expanding my collecting old computers: the cost and the space required to house them. I do have my old original TRS-80, and an old serial terminal (see the video below). However, I got rid of my Data General hardware and I lost my old 1802 COSMAC Elf in some flooding. There have been a few replica retro computers of various degrees of fidelity and they are usually cheaper and smaller than the originals. I have a replica Altair, a replica Elf, and a replica KIM-1.

However, it is hard to justify the expense and the cost of either the real things or the replicas. It is even worse with the really large machines, some of which require special power or cooling and are hard to keep running. Another option, of course, is software simulation. Options like SIMH and Hercules work well, but they aren’t always graphical and it is a lot of work to set up a machine just to play with for a few hours or to show a student how it was done in the good old days.

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Hackaday’s Omaha Mini Maker Faire Roundup

September 26, 2015 by Kristina Panos 3 Comments

The 2nd annual Omaha Mini Maker Faire wasn’t our first rodeo, but it was nonetheless a bit surprising . Before we even made it inside to pay our admission to the Omaha Children’s Museum, I took the opportunity to pet a Transylvanian Naked Neck chicken at one of the outdoor booths. The amiable fowl lives at City Sprouts, an Omaha community farming collective in its 20th year of operation. There seemed to be a theme of bootstrappy sustainability among the makers this year, and that’s great to see.

Just a few feet away sat a mustard-colored 1975 Chevy pickup with a food garden growing in its bed. This is Omaha’s truck farm, an initiative that seeks to educate the city’s kids in the ways of eating locally and growing food at home. On a carnivorous note, [Chad] from Cure Cooking showed my companion and me the correct way to dry-cure meats using time-honored methods.

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The Ubiquitous Atari Punk Console

September 17, 2015 by Nava Whiteford 11 Comments

The Atari Punk Console (APC) is a dual 555 (or single 556) based synth. Designed by the famous (and somewhat infamous) Forrest Mims in 1980 and originally simply named “Sound Synthesizer”, the circuit gained it’s more recent popularity when re-dubbed the “Atari Punk Console” by Kaustic Machines. The circuit however doesn’t bear much relation to the Atari 2600 which didn’t contain a 555 timer chip. However we assume the 2600 produced a similarly glitchy square wave audio output.

The circuits operation is easy to grasp and uses only 9 components. This ease of design and construction has allowed builders to focus more on the aesthetics of its construction, hacking it into interesting, and often unlikely enclosures and systems. One such hack is the “Atari Punk Bucket” (shown here) where the APC along with a simple amp was hacked into an old rusted bucket. The APC was built up on strip-board along with a simple amp and reclaimed speakers. [Farmer glitch] has used this as a prop in live sets and it both looks and sounds awesome. Continue reading “The Ubiquitous Atari Punk Console” →

AvE Builds DRINKO (not Affiliated With PLINKO)

September 16, 2015 by Adam Fabio 4 Comments

[SuperUnknown] aka [AvE], one of our favorite Canadian hackers is back at it with DRINKO, an adult beverage themed take on the classic PLINKO game from The Price Is Right. He’s built the game as a mancave warming gift for a friend. This isn’t a particularly complex build, but it’s always great to see all the little steps that go into a project, leading up to the finished job. [SuperUnknown] said that wood would be a great material for this project, but he is opposed to the senseless killing of peaceful trees, so he built the base from 1/8″ plate steel. The glasses were plain shot glasses masked and etched to spell out DRINKO.

The most tedious part of a fabricating a game like this is cutting and installing the tines. [SuperUnknown] used old welding rods, cut with a slitting saw on his Bridgeport. The rods were TIG welded into the metal plate forming the back panel of the game. To spice things up, [SuperUnknown] added an Arduino and some through hole WS2812 LEDs. While he didn’t have the flat surface mount WS2812’s on hand, that didn’t stop him. A quick trip through the bridgeport trimmed those frosted LED lenses down to size. The Arduino drives the LEDs through several patterns – much like the attract mode on a video game, or a Las Vegas sign. If you build your own DRINKO, we’d suggest adding some microswitches below each slot, so the drink to be consumed lights up.

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Hacklet 74 – Well Balanced Projects

September 11, 2015 by Adam Fabio 1 Comment

Balance: we humans take it for granted. Without the sense of balance provided by our inner ears, we would have a hard time standing or walking around. What’s easy for us can be very hard for machines though. Projects that balance things have long been a challenge for engineers, makers and hackers. And rightly so, as building a machine to keep an object in balance often requires some novel electronic and mechanical solutions. This week’s Hacklet is all about projects that keep an object – or themselves – in balance.

We start with [Manuel Kasten] and Balance Wheel. Inspired by a project at Chaos Communication Congress, [Manuel] created a hack that looks timeless. A stainless steel ball is balanced on top of a wooden wheel. The system detects the ball’s position using a solar cell. More light on the cell means the ball is slipping off the wheel. The system counteracts this by spinning the wheel to oppose the falling ball. In the old days this would have been an analog system. [Manuel] made things a bit more modern by using an ATmega644p processor. The video shows the wheel spinning a bit fast, as the system was tuned for a ping pong ball rather than a heavy steel roller.

Next up is [Jason Dorie] with Sideway. Sideway is a two-wheeled skateboard that self-balances. One of the best parts of this project is that most of the mechanical components are from electric scooters, which means they are easy to source. The frame is even easier: A solid piece of plywood supports the rider and all the electronics. Two scooter motors are driven by a Sabertooth 2x32A motor controller. A Parallax Propeller performs the balancing act, obtaining IMU data from an ITG3200 digital gyro and an ADXL345 accelerometer. Speed is controlled by leaning forward and back, like a Segway. Steering is controlled by a Wiimote nunchuck. Sideway is powered by 3 cell LiPo batteries. [Jason] says this ride gets a lot of attention every time he takes it out.

[Dominic Robillard] developed his Stair-climbing self-balancing robot as part of his masters degree at the University of Ottawa. We don’t know what grade his advisors gave him, but we give this project an A+. The robot is a 4WD off-road monster. Two heavy-duty drive motors give it tank style steering. The most impressive part of the robot are the two arms which allow it to roll its entire chassis up and over obstacles which would stop much larger robots. [Dominic’s] robot isn’t just statically balanced though – it can rear up and ride on two wheels Segway style. If it does tip over, the arms will lift it right back up!

Finally, we have [Paul Bristow] with Terabalance. [Paul] got his hands on an early copy of the TeraRanger One, a Time of Flight (ToF) sensor developed at CERN. He decided to test it out by using it to balance a ping pong ball on a wooden bar. The sensor had to be slowed down quite a bit in this application, data is only read about 1000 times a second and averaged. An Arduino reads the distance data from the sensor and uses that data to drive a hobby servo. No PID loops here, in fact, Terabalance is a great example of how a proportional only system will hunt forever. That said, it is good enough to keep the ball on the balance bar.

There are a plenty of balancing projects on Hackaday.io. If you want to see more, check out the new well balanced project list! Did I miss your project? Don’t be shy, just drop me a message on Hackaday.io. That’s it for this week’s Hacklet, As always, see you next week. Same hack time, same hack channel, bringing you the best of Hackaday.io!

Scanning Electron Microscope Images And Animations Pulled By Impressive Teensy LC Setup

September 5, 2015 by Dan Maloney 29 Comments

When you’ve got a scanning electron microscope sitting around, you’re going to find ways to push the awesome envelope. [Ben Krasnow] is upping his SEM game with a new rig to improve image capture (video link) and more easily create animated GIFs and videos.

The color scheme of the SEM housing gives away its 80s vintage, and the height of image capture technology back then was a Polaroid camera mounted over the instrument’s CRT. No other video output was provided, so [Ben] dug into the blueprints and probed around till he found the high-resolution slow scan signal.

To make his Teensy-LC happy, he used a few op-amps to condition the analog signal for the greatest resolution and split out the digital sync signals, which he fed into the analog and digital ports respectively. [Ben] then goes into a great deal of useful detail on how he got the video data encoded and sent over USB for frame capture and GIF generation. Reading the ADC quickly without jitter and balancing data collection with transmission were tricky, but he has established a rock-solid system for it.

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The Kraakdoos — Musical Abuser Of An Ancient OpAmp

September 3, 2015 by Nava Whiteford 11 Comments

A friend from the newly founded Yeovil Hackerspace introduced me to a device known as “The Kraakdoos” or cracklebox.

The cracklebox is an early electronic instrument produced by STEIM in the 1970s. The instrument consists of a single PCB with a number of copper pads exposed on one side. The player touches the pads and the instrument emits… sounds which can perhaps best be described as squeeze and squeals.

While the cracklebox was original sold as a complete instrument, the device has been reverse engineered, and the schematic documented. What lies inside is quite fascinating.

The heart of the cracklebox is an ancient opamp, the LM709. The LM709 is the predecessor to the famous LM741. Unlike the 741 the 709 had no internal frequency compensation. Frequency compensation is used to intentionally limit the bandwidth of an opamp. As input frequency increases, the phase shift of the opamp also increases. This can result in undesirable oscillation, as the feedback network forms an unintentional phase-shift oscillator.

Most modern opamps have internal frequency compensation, but the 709 doesn’t. Let’s see how this is used in the cracklebox:

Rather than using the frequency compensation pins as intended the cracklebox just routes them out to pads. In fact the cracklebox routes almost all the pins on the opamp out to pads, including the inverting and non-inverting inputs. A single 1MOhm feedback resistor is used in a non-inverting configuration. However reports suggest the instrument can work without a feedback resistor at all!