Necessity is the mother of invention. It is also true that invention necessitates learning new things. And such was the case on the stormy Tuesday morning our story begins. Distant echos of thunder reverberated in the small 8 x 16 workshop, drawing my attention to the surge suppressor powering my bench. With only a few vacation days left, my goal of finishing the hacked dancing Santa Claus toy was far from complete. It was for a Secret Santa gift, and I wanted to impress. The Santa moved from side to side as it sang a song. I wanted to replace the song with a custom MP3 track. In 2008, MP3 players were cheap and ripe for hacking. They could readily be picked up at local thrift shops, and I had picked up a few. It soon became clear, however, that I would need a microcontroller to make it do what I wanted it to do.
While most people who build their own computer from chips want the finished product to do something useful, there’s something to be said about a huge bank of switches and a bunch of blinkenlights. They’re incredibly simple – most of the time, you don’t even need RAM – and have a great classic look about them.
[Jim] wanted to build one of these computers and wound up creating a minimal system with switches and blinkenlights. It’s based on the Z80 CPU, has only 256 bytes of RAM, and not much else. Apart from a few extra chips to output data and address lines to LEDs and a few more to read switches, there are only two major chips in this computer.
With the circuit complete, [Jim] laser cut a small enclosure big enough to house his stripboard PCB, the switches and LEDs, and a few buttons to write to an address, perform a soft reset, and cycle the clock. One of the most practical additions to this switch/blinkenlight setup is a hand crank. There’s no crystal inside this computer, and all clock cycles are done manually. Instead of pushing a button hundreds of times to calculate something. [Jim] added a small hand crank that cycles the clock once per revolution. Crazy, but strangely practical.
[Jim] made a demo video of his computer in action, demonstrating how it’s able to calculate the greatest common divisor of two numbers. You can check that video out below.
A few old timers may remember that once, long ago, computers didn’t require keyboards. The earliest personal computers such as the Altair 8800 and the server rack-sized minicomputers like the PDP-11 could be controlled with a panel filled with switches and lights, giving us the term blinkenlights. Today, most of these machines have been thrown away or locked up in museums and private collections; even if you were to get your hands on one of these control panels, you’ll have a heck of a time doing something useful with one.
Fear not, because [Jörg] has come up with a great way to control these blinkenlights and simulate the computers of yesteryear. He calls his build BlinkenBone, and it’s able to control the blinkenlight panels from dozens of historical computers and simulate every thrown switch and tiny light bulb.
BlinkenBone is a BeagleBone single board Linux computer running the SimH simulator for antique computers. Right now the BlinkenBone is able to simulate the PDP-1, PDP-8, PDP-11, a lot of old IBM machines, the Altair 8800, and even some HP boxes.
Without a BlinkenBone or similar simulation device, the still-surviving control panels for these computers are just pieces of art to hang on a wall. When they’re running a simulation of their original hardware that was long-lost to the scrap yard, they become the useful devices they once were. Also, it’s much easier to appreciate how far technology has come in the last 40 years.
You can check out a short demo of [Jörg] using his BlinkenBone on a PDP-11/40 after the break. Look at those lights go.
Because surplus LED panels from an early 1990s supercomputer is a completely reasonable thing to own, [William Dillon] set to work displaying them on his wall.
The LED panels came from a surplus CM-5 Connection Machine, best known from it’s role as the mainframe in Jurassic Park (only an empty case with LED panels were used in the movie). When not on Isla Nublar, the Connection Machine was a fabulous piece of engineering from the 1980s Artificial Intelligence revival. With some machines having 65,536 processors, it was used for AI research using Lisp (although we were never very good at Lisp.
[William] built a wooden frame out of 1×2 inch maple and installed an X10 module behind the panels as a remote switch. The panels themselves aren’t controlled by a computer, so the only thing left to do was to mount the power supplies. It’s impressive to see the massively over-engineered power supplies that were designed to source 5V @ 30A when the panels only draw 7 Amps. [William] says it was a design feature of the Connection Machine to spare no expense.
[William]’s next plan is to reverse engineer the panels to display custom messages, and we can’t wait to see what he comes up with. We can’t explain why, but we really want to build one of these panels. Check out the pictures of [William] decommissioning the CM-5.
Macetech’s ShiftBrite is a high-power RGB LED coupled with an Allegro A6281 backpack. The A6281 uses three 10bit pulse-width modulators to mix millions of colors using the red, green, and blue elements in the RGB LED. Multiple modules can be chained together for bigger projects, like the ShiftBrite table.
We covered SparkFun’s new RGB button pad controller a few weeks ago. This is a full-color clone of the monome interface; a 4×4 grid of buttons with tri-color LEDs underneath. Each LED has 24bits of color control, for more than 16million color combinations. Up to 10 panels can be chained together to create huge button grids, like SparkFun’s Tetris table. We previously used a smaller version in our RGB combination lock.
We asked SparkFun to send us the SPI version of the button controller to test. This is a new product developed in-house at SparkFun, with open source hardware and software. Read about our experience interfacing this board below.
We’re happy to present this guest post from History Hacker’s [Bre Pettis]. Today [Bre] catches up with the Blinkenlights team, who turn entire buildings into displays. Their current project is Stereoscope which goes live in Toronto, Canada today.
Earlier this week, I posted about the beginnings of the blinkenlights project. It started in 2001 in Berlin, but now Seven years later, in May 2008, blinkenlights is back. The City of Toronto asked the blinkenlights team if they would be interested in joining another Nuit Blanche (as they did in Paris in 2002). Short on time and with a lot of ambition, they decided to redesign and push the envelope on the project to make it wireless for The Toronto City Hall since there would be 960 windows split up in two towers. In the above photo, you can see Stereoscope in all its glory. Continue reading “Blinkenlights’ Stereoscope goes live in Toronto”