Hackaday Retro Edition: Remaking The PDP 8/I With A Raspberry Pi

March 26, 2015 by Brian Benchoff 48 Comments

[Oscar] really likes the PDP-8s, with the extremely old school PDP-8/I being his favorite. If you haven’t checked the price on these recently, getting a real PDP-8/I is nigh impossible. However, after assembling a KIM-1 clone kit, an idea struck: what about building a modern PDP-8/I replica that looks like the real thing, but is powered by modern hardware. This would be fairly cheap to build, and has the added bonus of not weighing several hundred pounds.

The PiDP-8 is [Oscar]’s project to replicate the hardware of the 8/I in a modern format. Instead of hundreds of Flip Chips, this PDP-8 is powered by a Raspberry Pi running the SIMH emulator. The 40-pin GPIO connector on the Pi is broken out to 92 LEDs and 26 toggle switches on a large PCB. This setup gets [Oscar] a reasonable facsimile of the PDP-8/I, but he’s also going for looks too. He created an acrylic panel with artwork copied from an original 8/I that mounts to the PCB and gives the entire project that beautiful late 60s / early 70s brown with harvest gold accent color scheme.

Since this emulated PDP-8/I is running on entirely new hardware, it doesn’t make much sense to haul out disk drives as big as a small child, tape drives, and paper tape readers. Instead, [Oscar] is putting everything on USB sticks. It’s a great solution to the problem of moving around files that are a few kilowords in size.

[Oscar] says he’ll be bringing his PiDP to the Vintage Computer Festival East X in Wall, NJ, April 17-19. We’ll be there, and I’ve already offered [Oscar] the use of a VT-100 terminal. If you’re in the area, you should come to this event. It’s guaranteed to be an awesome event and you’re sure to have a great time. Since this is the 50th anniversary of the introduction of the PDP-8, there will be a half-dozen original PDP-8s set up, including a newly refurbished Straight-8 that came out of the RESISTORS.

Oh, if anyone knows how to connect a Pi to a VT100 (technically a 103), leave a note in the comments. Does it need the RTS/CTS?

SNES Headphones Cry For Bluetooth Has Been Answered

March 26, 2015 by Rich Bremer 3 Comments

A year and a half ago we ran a post about a SNES controller modified into a pair of headphones. They were certainly nice looking and creative headphones but the buttons, although present, were not functional. The title of the original post was (maybe antagonistically) called: ‘SNES Headphones Scream Out For Bluetooth Control‘.

Well, headphone modder [lyberty5] is back with a vengeance. He has heeded the call by building revision 2 of his SNES headphones… and guess what, they are indeed Bluetooth! Not only that, the A, B, X and Y buttons are functional this time around and have been wired up to the controls on the donor Bluetooth module.

To get this project started, the SNES controller was taken apart and the plastic housing was cut up to separate the two rounded sides. A cardboard form was glued in place so that epoxy putty could be roughly formed in order to make each part completely round. Once cured, the putty was sanded and imperfections filled with auto body filler. Holes were drilled for mounting to the headband and a slot was made for the Bluetooth modules’ USB port so the headphone can be charged. The headphones were then reassembled after a quick coat of paint in Nintendo Grey. We must say that these things look great.

If you’d like to make your own set of SNES Bluetooth Headphones, check out the build video after the break.

Continue reading “SNES Headphones Cry For Bluetooth Has Been Answered” →

Before Film There Were Zoetropes. Now We Have 3D Printed Zoetropes!

March 25, 2015 by James Hobson 15 Comments

Reddit user [eyelandarts] has produced a rather unique 3D printing project. A 3D printed Zoetrope.

You see, a zoetrope was a device that created an animation effect that pre-dates film technology. It would create the illusion of motion much like a flip book does, but with a spinning cylindrical wall with slots cut into it. As the cylinder spins, you catch a glimpse of the animation through the slots. But, it’s just a 2-dimensional animation — what if you replaced it with an ever changing 3D model?

It’s actually been done before. A long time ago in fact. In 1887, [Etienne-Jules Marey] created a large zoetrope to animate plaster models of a bird in flight. Fast forward to today, and [eyelandarts] has 3D printed something similar — but ditched the cylindrical wall. Instead, a strobe light is used to see the animation!

The end result is quite awesome if we do say so our-selves. For another fun take on Zoetropes — how about a digital one made out of tiny LCD screens?

Siezure-warning… there’s a very flash-tastic demo gif embedded after the break if you’re brave enough to view such a thing.

Continue reading “Before Film There Were Zoetropes. Now We Have 3D Printed Zoetropes!” →

New Part Day: MSP430 + Cortex M4F

March 25, 2015 by Brian Benchoff 41 Comments

Texas Instruments’ MSP430 series of microcontrollers has been the standard extremely low power microcontroller for several years now. It’s not an ARM, though, so while there are fans of the ‘430, there aren’t a lot of people who would want to port their work in ARM to a completely different architecture. Here is TI’s answer to that. It’s called the MSP432, and it combines the low power tech of the ‘430 with a 32-bit ARM Cortex M4F running at 48MHz.

This is not the first ARM Cortex M4F platform TI has developed; the Tiva C series is based on the Cortex M4F core and was released a few years ago. The MSP432 is a little bit different, leveraging the entire development system of the MSP430 and adding a DSP engine and a FPU. If you’re looking for something that’s low power but still powerful, there you go. You can find the official press release here.

If you’d like to try out the MSP432, there’s a LaunchPad available. $13 to TI gets you in the door. The most capable MSP432 with 256 kB of Flash, 64 kB of SRAM, and 24 ADC channels hasn’t hit distributors yet, but you can sample it here.

Resource Monitoring Solution

March 25, 2015 by Anool Mahidharia 27 Comments

Electricity, Gas and Water – three resources that are vital in our daily lives. Monitoring them using modern technology helps with conservation, but the real impact comes when we use the available data to reduce wasteful usage over time. [Sébastien] was rather embarrassed when a problem was detected in his boiler only during its annual inspection. Investigations showed that the problem occurred 4 months earlier, resulting in a net loss of more than 450 cubic meters, equivalent to 3750 liters per day (about 25 baths every day!). Being a self professed geek, living in a modern “connected” home, it rankled him to the core. What resulted was S-Energy – an energy resource monitoring solution (translated) that checks on electricity, gas and water consumption using a Raspberry Pi, an Arduino, some other bits of hardware and some smart software.

[Sébastien] wanted a system that would warn of abnormal consumption and encourage his household folks to consume less. His first hurdle was the meters themselves. All three utilities used pretty old technology, and the meters did not have pulse data output that is commonplace in modern metering. He could have replaced the old meters, but that was going to cost him a lot of money. So he figured out a way to extract data from the existing meters. For the Electricity meter, he thought of using current clamps, but punted that idea considering them to be suited more for instantaneous readings and prone for significant drift when measuring cumulative consumption. Eventually, he hit upon a pretty neat hack. He took a slot type opto coupler, cut it in half, and used it as a retro-reflective sensor that detected the black band on the spinning disk of the old electro-mechanical meter. Each turn of the disk corresponds to 4 Watt-hours. A little computation, and he’s able to deduce Watt-hours and Amps used. The sensor is hooked up to an Arduino Pro-mini which then sends the data via a nRF24L01+ module to the main circuit located inside his house. The electronics are housed in a small enclosure, and the opto-sensor looks just taped to the meter. He has a nice tip on aligning the infra-red opto-sensor – use a camera to check it (a phone camera can work well).

Continue reading “Resource Monitoring Solution” →

MRRF: Hot Ends, Extruders, Extremely Posh Brits, And Stoic Swedes

March 25, 2015 by Brian Benchoff 26 Comments

As far as locations for the Midwest RepRap Festival go, it’s not exactly ideal. This is a feature, not a bug, and it means only the cool people come out to the event. There were a few people travelling thousands of miles across an ocean, just to show off some cool things they built.

Two Colors, One Nozzle

[Sanjay] and [Josh] from E3D came all the way from merry olde England to show off a few of their wares. The star of their show was the Cyclops extruder, a dual-extrusion hot end that’s two input, one output. Yes, two colors can come out of one nozzle.

If you see a printer advertised as being dual extrusion, what you’re going to get is two extruders and two hot ends. This is the kludgy way to do things – the elegant solution is to make two colors come out of one nozzle.

The guys from E3D were showing off a few prints from their Cyclops nozzle that does just that, including a black and red poison dart frog, and a blue and white octopus. The prints looked amazing, and exactly what you would expect from a two-color print.

Rumor has it the development of the Cyclops involved extruding two colors, freezing the nozzle, and putting it in the mill just to see how the colors mixed. I didn’t see those pictures, but there’s a lot of work that went into this hot end.

The Power of Two Extruders

[Martin] of bondtech.se came to MRRF all the way from Sweden. He was there showing off his new extruder.

The extruder uses a normal stepper motor, but instead of the usual knurled or threaded feed wheel and bearing to push filament though, he’s using two counter-rotating feed wheels attached to a planetary gear system. That’s a lot of torque that doesn’t distort or strip the filament. When you consider all the weird filaments that are coming out – ninjaflex, and even 3D printable machinable wax filament, this is extremely interesting.

Even if your filament isn’t exactly 1.75 or 3mm in diameter, this setup will still reliably push plastic; there is a bolt that will move one of the feed wheels in and out 0.4mm.

[Martin] had a pair of his extruders hooked up to a strain gauge, and it’s strong enough to lift your printer off the table without stripping the filament. Here’s a video of that demo from the bondtech page.

Mustachioed Nintendo Virtual Boy Gone Augmented Reality

March 25, 2015 by Adam Fabio 14 Comments

Some people just want to watch the world burn. Others want to spread peace, joy and mustaches. [Joe Grand] falls into the latter group this time around. His latest creation is Mustache Mayhem, a hack, video game, and art project all rolled into one. This is a bit of a change from deconstructing circuit boards or designing electronic badges, but not completely new for [Joe], who wrote SCSIcide and Ultra SCSIcide for the Atari 2600 back in the early 2000’s.

Mustache Mayhem is built into a Nintendo Virtual Boy housing. The Virtual Boy itself was broken, and unfortunately was beyond repair. [Joe] removed most of the stock electronics and added a BeagleBone Black, Logitech C920 webcam, an LCD screen and some custom electronics. He kept the original audio amplifier, speakers, and controller connector. Angstrom Linux boots into [Joe’s] software, which uses OpenCV to detect faces and overlay mustaches. Gameplay is simple: Point the console at one or more faces. If you see a mustache, press the A button on the controller! The more faces and mustaches on-screen at once, the more points, or “mojo” the player gets. The code is up on Github, and can be built with Xcode targeted to the Mac, or directly on the BeagleBone Black.

[Joe’s] goal for the project was to make a ridiculous game that looks like it could have come out in the 90’s. He also used Mustache Mayhem as a fun way to learn some new skills which will come in handy for more serious projects in the future.

We caught up with [Joe] for a quick interview about his new creation.

How did you come up with the idea for Mustache Mayhem?

I was selling a bunch of my video game collection at PRGE (Portland Retro Gaming Expo) a few years ago and had a broken Virtual Boy that no one bought. A friend of mine was at the table and said I had to do something with it. I thought “People wear cosplay and walk around at conventions, so what if I could do something with the Virtual Boy that you could walk around with?” That was the seed.

A few months later, Texas Instruments sent me the original production release of the BeagleBone Black (rev. A5A). Eighteen months after that I actually started the project. The catalyst was to do something for an upcoming Portland, OR art show (Byte Me 4.0), which is an annual event that shows off interactive technology-based artwork. I wrote up a little description and got accepted. I had less than 2 months to actually get things working and it ended up taking about a month of full-time work. It was much more work than I expected for such a silly project. I originally was going to do something along the lines of walking around in a Doom-like perspective and shooting people when their faces were detected.

That would be pretty darn cool. How did you get from Doom to Mustaches?

I saw a TI BeagleBoard demo called “boothstache” which drew mustaches on faces and tweeted the pictures. I thought that doing something non-violent with mustaches would be more suitable (and funny) to actually show my kids. I also secretly wanted to use this project as a way to experiment with Linux, write some code, and learn about face detection and image processing with OpenCV, which I plan to use for some actual computer security research in the future. Mustache Mayhem turned out to be a super cool project and I’m really happy with it. I sort of feel guilty spending so much time on it, since it’s basically just a one-off prototype, but I just got so obsessed with making it exactly as I wanted.

You mentioned on your website that Mustache was “designed to challenge the paradigms of personal privacy and entertainment.” What exactly did you mean there?

Continue reading “Mustachioed Nintendo Virtual Boy Gone Augmented Reality” →