Ask Hackaday: Who Likes Retrocomputing?

September 15, 2012 by Brian Benchoff 54 Comments

Last week we posted a link to Project Kiwi, a homebrew Motorola 68008-based microcomputer built by [Simon] that includes Ethernet, a very good display adapter, an interface for IDE hard disks, two Commodore SID chips (for stereo chiptunes), a floppy disk controller, and an already existent software library that will make it very easy to develop your own software for this wonderful computer.

After thinking about [Simon]’s Project Kiwi for a while, I’ve been thinking there really hasn’t been a homebrew computer made that is so perfect for a proper Open Hardware release. There are more than enough peripherals in the computer to make development very fun. I’ve suggested doing a group buy to get Kiwi PCBs out into the wild and into the hands of other retrocomputer fanatics, but [Simon] would like a little more feedback.

Of course, this means turning to you, the wonderful Hackaday reader. Would any of you be interested in your own Kiwi microcomputer?

[Simon] tells me there are a lot of problems for turning the Kiwi microcomputer into a Open Hardware project. His prototype PCB cost €300, greatly reducing the number of people who would be interested in making their own Kiwi. Also, there are a few problems on the current PCB design (easily fixed for the next revision), and [Simon] would like to add a few features like DMA and a proper framebuffer.

Despite all those problems, I can’t see a better way to learn about computer architecture the hard way (i.e. 80’s microcomputers as opposed to futzing around with a Raspberry Pi). You’ll also get a really wonderful computer system that will show the power of 80s-era electronics, with the very hopeful goal of spreading the gospel of retrocomputing with the venerable Saint MC68000.

If you’d like to add your two cents – if having an Open Hardware 80s microcomputer is a good idea, or some technical requests such as adding a proper 68000 CPU to future designs, leave a note in the comments or on the forum [Simon] set up on his Kiwi page.

I think it’s a cool idea, but then again I’m probably blinded by how cool an 80s computer of this caliber is. The fate of this project is now in your hands.

ATtiny Controlled Magic Eye Tube

September 12, 2012 by Brian Benchoff 9 Comments

In the early days of broadcast radio, the most expensive radio sets were extremely impressive pieces of furniture. With beautifully crafted wooden cases polished to a high shine, these wireless receivers were the focal point of any family room. Some of the most expensive radio sets even included a visual indicator signaling the strength of the reception, something [Marcus] decided to re-engineer using an ATtiny85.

The display tube in question is an EM800 magic eye tube, used in radio sets, stereos, and electronic test equipment as a rudimentary display indicator. By applying a control voltage (from 0 to -10V), the illuminated display can be controlled like a bar graph display.

[Marcus]’ tube display is built around an ATtiny85 microcontroller, using a homemade PCB. It’s a fairly simple build, once the issue of supplying 250 Volts to the EM800’s anode is taken care of.

In the video after the break, you can see the bar display of [Marcus]’s magic eye tube slowly growing and receding, perfect for either displaying the current CPU load on your computer or anything else a dynamic bar graph display would be used.

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Typewriter Is USB Keyboard, Also Awesome

September 11, 2012 by Brian Benchoff 15 Comments

If you’re a brooding author putting the finishing touches on the next Great American Novel™ while sipping a latte in Starbucks, a MacBook is far too common to impress uncultured proles guzzling caramel macchiatos. No, to impress the next [Joyce] or [T. S. Eliot] sitting at the table next to you, you’ll need something much more hip, like a kit to turn a typewriter into a USB keyboard.

This kit to turn an old Underwood into a USB keyboard comes from the drawing board of [Jack Zylkin], member of Philly hackerspace Hive 76. [Jack] managed to make the process of turning an old typewriter into a keyboard a relatively painless process.

[Jack] created a sensor board loaded up with 74HC595 shift registers that easily mounts to the frame of just about any typewriter. When a key on the typewriter is struck, the mechanical levers strike metal strips soldered to the sensor board. An ATMega microcontroller records these keypresses and sends them over a USB port just like any other USB keyboard.

Modifying a typewriter into a USB keyboard is one of those projects we’d dread; you’d think there would be far too much futzing about with a lot of small electrical contacts and dirty mechanical devices. [Jack] actually managed to put together a very nice kit to turn a typewriter into a keyboard here.

You can pick up a kit over at [Jack]’s etsy store, but doing the same thing with a bit of perf board isn’t out of the question. Awesome video after the break.

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Building The Best Homebrew Computer Ever

September 8, 2012 by Brian Benchoff 22 Comments

A few days ago when I posted a homebrew Motorola 68000 computer spectacular, I briefly mentioned a truly spectacular homebrew computer built by [Simon Ferber]. When I posted a link to a Youtube demo of his 68k board, he was working on a website to document the architecture design, hardware, and software. That website is now up (cache if you need it) and now we can all get a good look at the best homebrew computer ever built.

Built around the 68008 CPU – slightly less capable than the 68000 found in the original Macs, Amigas, and the TI-89 – [Simon]’s Kiwi computer has peripherals out the wazoo. A Yamaha V9990 Video Display Processor provides a 640×480 display with 32k colors. Two SID chips taken from a Commodore 64 provide stereo chiptune audio, and a floppy disk controller, IDE/ATA bus, and CS8900A Ethernet controller provide all the practical functionality you’d expect from an awesome computer.

On the software side of things, [Simon] is running Enhanced Basic 68k, but of course he can’t just use BASIC to fiddle around with all the cool chips on the Kiwi. With that in mind, he came up with a C-based toolchain that included porting libc to the Kiwi.

Like any good homebrew computer project, all the schematics, a bit of code, and a BOM are provided. [Simon] is currently working on (slightly) redesigning the PCB layout of the Kiwi, and we’ll be happy to see those files released. Anyone up for a Kiwi PCB group buy?

Homebrew 68k Extravaganza

September 4, 2012 by Brian Benchoff 45 Comments

Introduced in 1979, the Motorola 68000 CPU was first used in very expensive and very high-end workstations from the likes of Sun and SGI. As the processor matured it became well-known for its use in the original Macintosh, early Amigas, and even the TI-89 graphing calculator and a few video game consoles such as the Sega Genesis and Atari Jaguar.

A few days ago when I posted a homebrew computer build based on the 65816 CPU, I lamented the lack of builds using the venerable Motorola 68k. Hackaday readers were quick to point out the many homebrew computers making use of this classic CPU, and I’m glad to post them here.

First up is an amazing 68008 build featuring an IDE disk interface, a floppy disk interface, 10base-T Ethernet connectivity, a real-time clock, and two SID synthesizer chips. As far as features go, this build takes the cake. Pity I can’t find a writeup.

Here’s a 68000-based computer built around the S-100 bus. Like the first computer to use the S-100 bus, the Altair 8800, this computer is plugged into a backplane that breaks out the data, address, and interrupt lines to every device on the bus.

Of course, no mention of backplane computers would be complete without a Eurocard version. [N8VEM] built a 68000 computer able to be plugged in to a backplane along with an IDE controller card and a display controller.

Finally, in true ‘giant mess of wires’ spirit, [Dajgoro] sent in his 68k single board computer featuring 512 kB of RAM and a 16k ROM. [Dajgoro] also took the time to wire in a PIC microcontroller, allowing him to expand his computer far beyond what vintage components would allow.

The 68k was – and still is – a very powerful CPU that far surpasses the capabilities of the 6502 and Z80 homebrew computers we see from time to time. Short of building a 486 or Pentium-based computer from scratch, building a 68k machine is one of the crowning achievements of hardware hackery, and something we hope to see more of in the future.

Saving A Bricked Phone With A Pencil Lead

September 3, 2012 by Brian Benchoff 34 Comments

[stompyonos] bricked his Samsung Captivate. Not wanting to be without a phone for a while, he researched a fix online and found shorting a pair of pins on the USB port would put the phone into download mode, saving his phone. The only problem for this plan is [stompy] didn’t have any resistors on hand. Instead, he came up with a wonderful MacGyverism using a piece of paper, a bit of graphite, and a pair of paper clips.

The process of unbricking a Captivate requires a 300 or 330 kΩ resistor across pins 4 and 5 of the mini USB port. This can be done with a few resistors, but [stompy] only had a multimeter lying around. After scribbling a good bit of pencil lead on a piece of paper, he attached two paper clips to make a variable resistor, dialed it in to about 300 kΩ, and cut up an old Nokia charger for its USB plug.

Not bad for a very easy fix that didn’t cost [stompyonos] a dime, and certainly better than a $500 paperweight.

Turning A MIDI Sequencer Display Into A Tetris Clone

September 1, 2012 by Mike Nathan 11 Comments

led-midi-display-tetris

Tetris is unquestionably a game for the ages. Despite its simplicity, someone, somewhere will always find a way to port the game (Translation) to just about any electronic device that can handle it.

Earlier this year we showed you a slick MIDI sequencer project that was constructed using an Arduino Mega, which also happened to drive an incredibly detailed touch screen display. [Christian] must have gotten bored with his awesome creation one day, because he pulled the drum level display out of his Arduino Sequencer 808, and turned the LED array into a mini Tetris game.

As you can see in the video below, the game runs pretty well, though from what we can see it lacks any sort of score keeping. We dig it because we never really tire of Tetris clones, and we think it’s great that he kept his 808 sequencer design modular enough that he can pluck different components out for reuse in other projects.

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