A Z80 Retro Microcomputer For The Papilio Pro FPGA Board

z80

[Will] wrote a 128MHz Z80-based retro microcomputer which runs on a Papilio Pro board. For those who don’t know, the latter is built around a Spartan-6 LX9 FPGA so you may imagine that much work was required to implement all the computer features in VHDL. The T80 CPU core was taken from opencores, the SDRAM controller was imported from Mike Field’s work but [Will] implemented several additional functions on his own:

– a 4KB paged Memory Management Unit to translate the 16-bit (64KB) logical address space into a 26-bit (64MB) physical address space.

– a 16KB direct mapped cache to hide the SDRAM latency, using the FPGA internal block RAM

– a UART interface for external communications

He also ported CP/M-2.2, MP/M-II and UZI (a UNIX system) to the computer. His project is completely open-source and all the source code can be downloaded at the end of [Will]’s write up.

Thanks [hamster] for the tip.

Eye Tracking With The Oculus Rift

ocu

There’s a lot you can do with eye and gaze tracking, when it comes to interface design, so when [Diako] got his hands on an Oculus Rift, there was really only one thing to do.

Like a few other solutions for eye tracking we’ve seen, [Diako] is using a small camera with the IR filter removed to read the shape and location of an eye’s pupil to determine where the user is looking. This did require cutting a small hole near one of the Oculus’ eye cups, but the internal camera works great.

To get a window to the world, if it were, [Diako] slapped another camera onto the front of the Oculus. These two cameras are fed into the same computer, the gaze tracking is overlaid with the image from the front of the headset, and right away the user has a visual indication of where they’re looking.

Yes, using a computer to know where you’re looking may seem like a rather useless build, but stuff like this is used in research and extraordinarily high tech heads up displays. Although he’s not using the motion tracking on the Oculus, if [Diako] were to do so, he’d have the makings of one of the most powerful heads up displays possible.

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Hackaday Space: Transmission 3 Puzzles Explained

transmission-3-puzzles-explained

Yesterday we did a run down of Transmission 2 as part of a series of posts covering the ARG that we ran throughout April. Today I’m going to reveal all the details in Transmission 3, how we put it together and what the answers were.

In classic Hackaday fashion we hadn’t planned any of this, so by this point all our initial ideas we already used up and we were now running out of creativity so it was a real slog to get Transmission 3 out the gate. However we somehow managed it and opened Transmission 3 by posting a series of 5 images of space telescopes:

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Airchat, The Wireless Mesh Network From Lulzlabs

With the lessons learned from the Egyptian, Libyan, and Syrian revolutions, a few hardware and software hackers over at Lulzlabs have taken it upon themselves to create a free-as-in-beer and free-as-in-speech digital communications protocol that doesn’t deal with expensive, highly-surveilled commercial and government controlled infrastructure. They call it Airchat, and it’s an impressive piece of work if you don’t care about silly things like ‘laws’.

Before going any further, we have to say yes, this does use amateur radio bands, and yes, they’re using (optional) encryption, and no, the team behind Airchat isn’t complying with all FCC and other amateur radio rules and regulations. Officially, we have to say the FCC (and similar agencies in other countries) have been granted the power – by the people – to regulate the radio spectrum, and you really shouldn’t disobey them. Notice the phrasing in that last sentence, and draw your own philosophical conclusions.

Airchat uses an off the shelf amateur transmitter, a Yaesu 897D in the example video below although a $30 Chinese handheld radio will do, to create a mesh network between other Airchat users running the same software. The protocol is based on the Lulzpacket, a few bits of information that give the message error correction and a random code to identify the packet. Each node in this mesh network is defined by it’s ability to decrypt messages. There’s no hardware ID, and no plain text transmitter identification. It’s the mesh network you want if you’re under the thumb of an oppressive government.

Airchat has already been used to play chess with people 180 miles away, controlled a 3D printer over 80 miles, and has been used to share pictures and voice chats. It’s still a proof of concept, and the example use cases – NGOs working in Africa, disaster response, and expedition base camps – are noble enough to not dismiss this entirely.

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Mirror Mirror On The Wall…

Who wouldn’t want a mirror that compliments them first thing in the morning? [Michael]’s  Magic Mirror does this and more.  [Michael] got the idea for his mirror during an epic Macy’s shopping trip with his girlfriend. While looking for a boyfriend chair, [Michael] noticed a mirror with a lighted sign behind it. Intrigued by the effect, [Michael] realized he could build it – and build it better!

Back at home [Michael] set to work. The Magic Mirror uses a piece of one-way mirror, similar to infinity mirrors. Instead of LED’s and another mirror, [Michael] wanted to embed an entire monitor behind the glass. In order to keep the mirror thin, [Michael] needed a monitor with cables exiting toward the side or bottom rather than directly out the back. He found what he was looking for in an Iiyama monitor. Yanking the case off a brand new LCD can be a bit nerve-wracking, but [Michael] pulled it off in pursuit of a thin final product.

Magic Mirror’s frame is built with standard 2×4 lumber. [Michael] had the foresight to include some cooling holes for the heat generated by the monitor. The heavy 6.5Kg final product required a double mounting point.

With a good-looking case, it was time to get some equally good-looking data to display. [Michael] used a Raspberry Pi to drive his display. He switched the Pi’s display mode to portrait and installed Chromium  in kiosk mode. The entire mirror is essentially a web page. [Michael] used some simple HTML, CSS and Javascript to pull time and weather data down from various feeds. The page is rendered in a clean Helvetica Nueve Neue font with matching icons. A handsome build indeed!

Straw Based Filament?

Straw Based Filament

PLA (polyactic acid) is often toted as one of the most environmentally friendly and safe filaments for consumer printing, since it is derived from corn products — not fossil fuels. But there’s a new contender on the market, and that is a type of straw-based plastic filament — which also promises to cost around half as much!

Designed by a Chinese company called Jinghe, the material is made by grinding up various dried crops like wheat, rice, and cotton, which in China is typically burned to get dispose of. The sawdust is then mixed with additives like polypropylene, silane coupling agent, and ethylene bis(stearamide). It is then extruded into a pellets of uniform size to allow for easier processing. From there it can be used for injection molding (melting temperature between 160-180°C), or further extruded into filament form. The filament  and resulting prints are a woody color with an interesting fiber-like surface finish, with decent part strength.

The company has signed a $320,000 USD contract with the Shantou city government to produce this type of plastic for toys in the European market — If production ramps up, it could well become one of the cheapest filaments available!

We like to cover all these alternative filaments as they come out, and there is becoming quite a selection! If you hear of any new materials used for printing, don’t forget to send them in to the tips line!

[Via 3ders.org]

C64 MIDI And Flash Cart

KerberosThe SID chip inside the Commodore 64 and 128 is arguably still the gold standard for chip tunes, and the C64 itself still a decent computer for MIDI sequencing. [Frank Buss] realized most of the MIDI cartridges for the Commodore computers are either out of production or severely limited, so he set out to create his own.

Unlike the few Commodore MIDI cartridges that are available, [Frank]’s Kerberos has MIDI In, Out, and Thru, controlled by the 6850 ACIA chip, just like the old 80s interfaces. This allows the Kerberos to interface with the old Sequential Circuits, Passport, and Datel software. He’s offering the Kerberos cart up on a crowdfunding site, so if you’d like to grab your own, have at it.

Because the Kerberos is also a Flash cart, it also ships with some of this software; [Frank] got permission from Steinberg to install their Pro 16 software with the Kerberos.  SID Wizard is also pre-loaded on the cart, along with a few other fabulous trackers and sequencers. Of course, there’s no requirement for the Flash portion of the cart to only host MIDI and synth software. You can always upload a few games to the cart over a MIDI interface. Video of the Kerberos below.

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