DIY 6502 Laptop Computer Looks and Works Great

Over the years, we’ve seen a lot of DIY retro computers, but [Dirk Grappendorf] has created one of the most polished looking 6502 systems to date. His battery-powered portable machine utilizes a 4 line by 40 character LCD, and a modified USB keyboard. Cover all that in a slick 3D printed case, and you have a machine that reminds us quite a bit of the venerable TRS-80 Model 100.

homecomputer-6502-v8-via-bread[Dirk] has some great documentation to go with his computer. He started with a classic MOS 6502 processor. He surrounded the processor with a number of support chips correct for the early 80’s period. RAM is easy-to -use static RAM, while ROM is handled by UV erasable EPROM. A pair of MOS 6522 Versatile Interface Adapter (VIA) chips connect the keyboard, LCD, and any other peripherals to the CPU. Sound is of course provided by the 6581 SID chip.  All this made for a heck of a lot of wires when built up on a breadboard. The only thing missing from this build is a way to store software written on the machine. [Dirk] already is looking into ways to add an SD card interface to the machine.

homecomputer-6502-final-4The home building didn’t stop there though. [Dirk] designed and etched his own printed circuit board (PCB) for his computer. DIY PCBs with surface mount components are easy these days, but things are a heck of a lot harder with older through hole components. Every through hole pin and via had to be drilled, and soldered to the top and bottom layers of the board. Not to mention the fact that both layers had to line up perfectly to avoid missing holes! To say this was a lot of work would be an understatement.

homecomputer-6502-final-5[Dirk] designed a custom 3D printed case for his computer and printed it out on his Ultimaker. To make things fit, he created his design in halves, and glued the case once printing was complete.

If awesome hardware and a case weren’t enough, [Dirk] also spent time designing software for the machine. He wrote his own abbreviated BASIC interpreter along with several BASIC programs. You can find everything over on his GitHub repository.

We always love writing up well-documented, and just generally awesome projects like [Dirk’s]. If you know of any retro computers like this one, drop us a tip!

[Thanks MicroHex!]

Trinket uses RF to track you through the house

If you carry a cell phone with GPS, you always know where you are on the planet. But what about inside buildings or even your own home? Knowing if you’re in the kitchen or the living room would be a great feature for home automation systems. Lights could come on as you enter the room and your music could follow you on the home audio system. This is exactly the what [Eric] is working on with his Radiolocation using a Pocket Size Transceiver project. [Eric] started this project as an entry in the Trinket Everyday Carry Contest. He didn’t make the top 3, but was one of the fierce competitors who made the competition very hard to judge!

The heart of the project is determining Time Of Flight (TOF) for a radio signal. Since radio waves move at the speed of light, this is no small feat for an Arduino based design! [Eric] isn’t re-inventing the wheel though – he’s basing his design on several research papers, which he’s linked to his project description. Time of flight calculations get easier to handle when calculating round trip times rather than one way. To handle this, one or more base stations send out pings, which are received and returned by small transponders worn by a user. By averaging over many round trip transmissions, a distance estimation can be calculated.

[Eric] used a Pro Trinket as his mobile transponder, while an Arduino Micro with it’s 16 bit counter acted as the base station. For RF, he used the popular  Nordic nRF24L01+ 2.4 GHz transceiver modules. Even with this simple hardware, he’s achieved great results. So far he can display distance between base and transponder on a graph. Not bad for a DIY transponder so small if fits in a 2xAAA battery case! [Eric’s] next task is working through multipath issues, and testing out multiple base stations.

Click past the break to see [Eric’s] project in action!

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3D Printed LED Guitar Chord Chart

Learning to play guitar can involve a lot of memorization – chords, scales, arpeggios, you name it. [MushfiqM] has made the process a bit easier with his Digital Chord Chart. Just about every beginning guitarist keeps a chord app, chord book, or even a chord poster handy. Usually these chord charts are in the form of tablature, which is a shorthand method of showing where each finger should go on the instrument. [MushfiqM] took things a step further by actually placing that chart on a 3D printed model of a guitar fretboard.

ledmatrixx[MushfiqM] started by rendering a 3D model of an abbreviated guitar using Autodesk Inventor. He then printed his creation in 3 parts: headstock, neck, and fretboard. The neck of the guitar was hollowed out to allow room for a matrix of LEDs which would show the finger positions. [MushfiqM] then painstakingly soldered in a charlieplexed matrix of 30 leds, all connected by magnet wire. The LEDs are controlled by an Arduino UNO, which has the chord and scale charts stored in flash.

For a user interface, [MushfiqM] used a 2×16 character based LCD and a low-cost IR remote control. All the user has to do is select a chord or scale, and it’s displayed on the fretboard.

There are a couple of commercial products out there which perform a similar function, most notably the Fretlight guitar. Those can get a bit pricy though – costing up to $400.00 USD for an LED enabled guitar.

[via Instructables]

Arduino Reads Punch Cards

Punch cards were a standard form of program and data storage for decades, but you’d never know it by looking around today. Card punches and even readers are becoming rare and expensive. Sometimes it takes a bit of hacking [YouTube link] to get that old iron running again!

[Antiquekid3] managed to score an old punch card reader on Ebay, but didn’t have a way to interface with it. The reader turned out to be a Documation M-1000-L. After a bit of searching, [Antiquekid3] managed to find the manual [PDF link] on BitSavers. It turns out that the Documation reader used a discrete output for each row of data. One would think the Documation reader would be a perfect fit for the PDP-8 lurking in the background of [Antiquekid3’s] video, but unfortunately the ‘8 lacks the necessary OMNIBUS card to interface with a reader.

Undaunted, [Antiquekid3] threw some modern hardware into the mix, and used an Arduino Uno as a Documation to Serial interface. The Arduino had plenty of I/O to wire up with the card reader’s interface. It also had a serial interface which made outputting data a snap. The ATmega328 even had enough power to translate each card from one of IBM’s many keypunch formats to serial.

[Antiquekid3’s] test deck of cards turned out to be a floating point data set. Plotting the data with a spreadsheet results in a nice linear set of data points. Of course, no one knows what the data is supposed to mean! Want more punch card goodness? Check out this tweeting punch card reader, or this Arduino based reader which uses LEGO and a digital camera to coax the data from the paper.

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Hacklet 30 – Robot Arm Projects

Robot arms – they do everything from moving silicon wafers to welding cars. Many a hacker has dreamt of having their own robot arm to serve them beer help them build projects. This week’s Hacklet features some of the best robot arm projects on!

robotarm1We start with [4ndreas] who is building this incredible 3D Printable Robot Arm. Inspired by large industrial robots, [4ndreas] has given us an entirely 3D printable design. [4ndreas’] 3D design experience really shows here. This arm looks like it just finished work at a local assembly line! The arm is BIG too – printing the parts took him about a week, and used around 1.2kg of ABS filament! [4ndreas] has recently split the project off into two halves: his blue arm is driven by stepper motors, while the orange arm is a DC motor affair. Both of the arms can use his awesome gripper design. Check out the project page for videos of the arm in action!

6dofarmNext up is [Dan Royer] and his 6DOF Robot Arm. [Dan’s] didn’t want to spend upwards of $10,000 on an industrial arm, so he built his own from wood, plastic, and easily obtainable parts. As the name implies, the arm has 6 degrees of freedom. The electronics consist of beefy NEMA 17 stepper motors and a RUMBA controller, which was originally designed for 3D printers. Dan even created some novel encoder mounts. Each joint has an encoder, which will allow the robot to run as a closed loop system. [Dan] originally entered this arm in The Hackaday Prize 2014. While it didn’t get him to space, we’re betting it will be able to get him a soda!


No robot arm Hacklet would be complete without featuring [ben.phenoptix] and the awesome MeArm. MeArm is a pocket-sized robot arm which uses tiny 9 gram servos for locomotion. It’s built from laser cut acrylic and standard hardware. We loved the MeArm so much that we featured it as one of the challenges in our Embedded Hardware Workshop in Munich. More recently, [Ben] and MeArm have had a great run on Kickstarter. Let’s hope those arms are good at stuffing, addressing, and mailing out packages!


owiFinally we have [Kenji Larsen] with Reactron material transporter. The material transporter is just a small part of [Kenji’s] larger Reactron project. It started with an OWI-535 robot arm. The OWI is really a toy – a plastic kit which builds an open loop DC motor driven arm. [Kenji] has put some serious time into modifying his particular arm. He experimented with molding his own potentiometers for each joint before settling on a printed circuit board based design. Once the new system was in place, he found that his resistors were good for about 10,000 cycles. Not bad for a modified toy!

There are quite a few robot arm projects we weren’t able to cover in this edition of The Hacklet – you can check them all out on our brand new Robot Arm Projects List!

That’s it for this Hacklet, As always, see you next week. Same hack time, same hack channel, bringing you the best of!

[Tesla500] Builds a High-Speed Video Camera

[Tesla500] has a passion for high-speed photography. Unfortunately, costs for high-speed video cameras like the Phantom Flex run into the tens or even hundreds of thousands of dollars. When tools are too expensive, you do the only thing you can – you build your own! [Tesla500’s] HSC768 is named for the data transfer rate of its image sensor. 768 megapixels per second translates to about 960MB/s due to the 10 bit pixel format used by the On Semiconductor Lupa1300-2 image sensor.

This is actually [Tesla500’s] second high-speed camera, the first was HSC80, based upon the much slower Lupa300 sensor. HSC80 did work, but it was tied to an FPGA devboard and controlled by a PC. [Tesla500’s] experience really shows in this second effort, as HSC768 is a complete portable system running Linux with a QT based GUI and a touchscreen. A 3D printed case gives the camera that familiar DSLR/MILC  shape we’ve all come to know and love.

The processor is a Texas Instruments TMS320DM8148 DaVinci, running TI’s customized build of Linux. The DaVinci controls most of the mundane things like the GUI, trigger I/O, SD card and SATA interfaces. The real magic is the high-speed image acquisition, which is all handled by the FPGA. High-speed image acquisition demands high-speed memory, and a lot of it! Thankfully, desktop computers have given us large, high-speed DDR3 ram modules. However, when it came time to design the camera, [Tesla500] found that neither Xilinx nor Altera had a FPGA under $1000 USD with DDR3 module support. Sure, they will support individual DDR3 chips, but costs are much higher when dealing with chips. Lattice did have a low-cost FPGA with the features [Tesla500] needed, so a Lattice ECP3 series chip went into the camera.

The final result looks well worth all the effort [Tesla500] has put into this project. The HSC768 is capable of taking SXGA (1280×1024) videos at 500 frames per second, or 800×600 gray·scale images at the 1200 frames per second. Lower resolutions allow for even higher frame rates.  [Tesla500] has even used the camera to analyze a strange air oscillation he was having in his pneumatic hand dryer.  Click past the break for an overview video of the camera, and the hand dryer video. Both contain some stunning high-speed sequences!

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R/C Wheel Loader Clears Snow, Lifts People

For some people, R/C cars just aren’t enough. [djMedic2008] has gotten his hands on a monstrous 1/5 scale wheel loader. The loader weighs in at 500lbs, and can lift up to 250 lbs. It was built several years ago as a prototype by [Richard] at Tiny Titan Earth Movers.

The design is based upon huge machines made by companies like Caterpillar and Komatsu. The 4WD system is driven a DC motor through a worm gear reduction. Bucket operation and steering are both operated by a hydraulic system driven by an electric pump. Just like the full-scale machines, the mini loader uses an articulated steering system. The front wheels are locked in place while the entire chassis bends at the middle pivot point. This allows for a much stronger solid front axle.

loader-gearAfter several years of hard life, the loader came to [djMedic] in need of some TLC. The biggest issue was that the rear axle bevel gear had lost several teeth. This gear is under enormous loads when the loader is turning. A gear made of harder steel was the easy answer. Thankfully, you can order high carbon steel bevel gears from Amazon. The repair video gives us a look at the design of the loader. The main components of the machine are welded up from steel sheet and tube stock. This means that [djMedic] won’t have a hard time finding spare parts for his machine once he puts it to work clearing snow, dirt, or anything else that gets in its way!

Click past the break to see the loader in action!

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