Saturday, June 28, 2008

TRS-80 Model III

This is a functioning TRS-80 Model III. It has 48k ram, a 2.03MHZ processor, and built in support for basic. In this picture, it is running a basic program. The only (but not so minor) problem with this unit is the fact that there is graffiti written in sharpie on the monitor.


This is an IBM PCjr. It has three ROM cartridges, one of them being BASIC. It also has the DOS boot disk. Unfortunately, I couldn't find an appropriate power cord to plug it in with, so I was unable to test the unit.

Thursday, June 26, 2008

Electric Motorbike Conversion

Old Bike Frame

Forklift Motor


Vroom! will probably be more of an electric-sounding whine. Anyways, the motorbike was stripped of its engine, gas tank, transmission, and the rest of its innards. The forklift motor was pulled out of a dead forklift. A basic prototype using a different bike frame and motor was demonstrated at the last Maker Faire. When this thing is finished, it will make for one hell of a stealth bike, and will eventually make use of those heatsinked mosfets in the UPS's as explained a couple posts back. Here is a pic of the older version, which is using a different frame and motor:

Water Electrolysis Machine

This interesting box, manufactured by Stan Rubinstein Associates, is a gas generator designed for welding. It takes in standard wall current, water, boric acid, and spits out two pipes of hydrogen and oxygen gas to weld with. Many possible applications. With a compressor, for example, the hydrogen gas could be stored in a high-pressure tank for use in a hydrogen car.

Clustering Projects

Over the years, there has always been some sort of cluster development or another going on. At the moment, we are experimenting with Instant-Grid.Above: a stack of relativly fast pentium 4 nodes.
Above: the master node under the table and its monitor.
Below: a close-up of the master running Instant-Grid.
Before experimenting with Instant-Grid, we used a custom build of Parallelknoppix. When using it, at least three big/notable povray rendering clusters were made (probably more which I can't remember.) But Instant-Grid has a lot more features, and although its documentation is half in German, it is remerkably easy to use.

Wednesday, June 25, 2008

Computer Case Mod

There was an old dead TV lying around, and it was decided to turn it into a computer. Here are the preliminary results:
[front view] - The screen reflection is of my eeepc which I used to take this pic. The pictures are too dark because of the poor lighting conditions in the warehouse, and I was using the eeepc's built in camera instead of the regular camera.

[back view]

Note I described it with the adjective "preliminary." The power supply has not yet been mounted, and several other parts have yet to be mounted properly. Also, there's a static electricity buildup problem resulting from the lack of a proper ground in the case, which stops the screen from operationg properly.

UPS's, MOSFETS, PWM and more!

This post will discuss an idea related to the circuitry inside UPS's and a possible application. Now I don't take credit for this idea, I am posting it here to get input on whether you/readers think it is feasible, or have any suggestions on its implementation.This is a picture of the circuit board of a UPS. There are many dead UPS's lying around the ACCRC.
This is a closeup of a bunch of the heatsink, which cools off a group of mosfets wired in parallel, the main current shifter. Each one of these mosfets, an irf3710, is capable of dissipating 50 watts. (according to the irf3710 datasheet) So together, they can supply 1000 watts, easily enough for a powerful motor.

The idea is to take these mosfets, and use them as the basis for a scalable high-wattage motor controller. When I was building a robot (more on that in a later post), the hardest part of the initial hardware design was getting a motor controller circuit which could put out suitable current to drive the motors. Motor controllers are expensive, and the lack of them is the main restricting factor of a lot of the electric vehicle/robot work that goes on here. Anyways, the mosfets would be wired in parallel, allowing for scalability. They would take input from a computer or a microcontroller which puts out PWM, like the arduino board, or the circuit based off a parallel port, as described at

Combined with easy pwm circuitry, these mosfet arrays will make it a heck of a lot easier and cheaper to conduct robotic and electric vehicle research. Any questions/suggestions?

Big Servers

Among all the computers and electronics here at the ACCRC, there are servers with a nice chunk of processing power available, sitting around and gathering dust. Some of the less heavy (weight and power) ones are being turned into Ubuntu install servers. These ones are just sitting around being useless at the minute. There are two I have documented, a Sun Enterprise 450 and an IBM 9406-5xx. Both appear to turn on and run, and I am focusing on the Enterprise for diagnosis because it has a VGA-compatible card and a serial port for input. (grrr... proprietary sun mouse/keyboard connector)

IBM 9406-5xx:

Sun Enterprise 450:

Are there any ideas on what these could be repurposed to do? Anyone going to slip us a fat wad of cash in exchange for either of them? Or does anyone know about getting by the system key protection on the 9406, or if it's even possible?

Apple ][ e

This is an Apple IIe, with a disk drive attachment and monitor. In this particular unit, the back panel's connector for the disk drive has broken off, rendering the disk drive useless. Also, there is a key missing on the keyboard. Although there are a couple problems with this particular unit, there are a couple more lying around. (This one was the only one already connected to a monitor, making it convienient to test)
A simple basic program running on it.

Saturday, June 21, 2008

Old Calculators

These are two old (older than the Wang, see earlier post) calculators, pre-pre-cursors to computers. Neither of them are fully transistorized, they incorporate mechanical parts to assist in performing calculations.
The top one was made by Burroughs, and the bottom one made by Friden.

8-Track Stereo

An 8-Track player stereo system. It can also play AM and FM radio. It hasn't been tested, but appears to be in fine condition. As seen below, it can fold out, and is very portable.

Cluster nodes

There are many, many, computers lying around the ACCRC. These are pictures of but a few of them. In the past, clusters have been made, usually running povray on parallelknoppix. They rendered pictures which were converted into animations.

With all this computing power available, what other kinds of distributed clustering jobs are possible? Any ideas?

Wang 600

This is a Wang 600 programmable calculator. A sticker on the back reveals that it was made in 1974, and serviced on 1978. It seems to function properly, despite the bits of what appears to be wood and other crap which has fallen under the keys. In addition, the cassette drive has some shavings in it, and has been drawn on with pastel. There are more of them in a pile somewhere, and this particular one was the most accessible one to blog about.

What makes this really interesting (aside from collectibility) is the fact that there are two i/o ports on the back, and that there is a Fortran compiler online for it, creating many opportunities for hacking and the like. Also, the name of the system leads to many rather amusing/crude jokes ("We at the ACCRC would like to show you our wangs").

Digital Trainer

This is a rather unusual item. It is a logic trainer k-80, a piece of hardware designed to train people in digital electronics. It has a breadboard, various buttons to control the clock, and places to plug in wires to connect the various components and circuits within. Seems like a good way to learn basic digital electronics.

WWII Oscilloscope

This is a WWII era oscilloscope in its carrying case. It is from the US Navy, and has a manual.

Above: out of its case
The manual.

Thursday, June 19, 2008

"Portable" Computers of the 80's

The Osbourne was the first portable computer, with a built-in keyboard, monitor, and power supply. It has a 4mhz processor, and 64k ram. This is an Osbourne 1(rev 1.43), it seems to function fine, but there's no boot disk, so testing remains to be done.
Boot Message:
The Kaypro series eventually superseded the Osbournes, and took over the portable computer market. This is a Kaypro II on boot screen, waiting for a boot disk.
Here is the Kaypro II again folded up.
Damn, these are old, clunky, and slow. Especially compared to modern laptops and computers.

Ultrasound Machine

This is an ultrasound machine. It is unknown whether it works or not, but all the pieces are here, it seems. What should be done about it? I don't plan on delivering any babies in the foreseeable future, so a whole machine isn't useful. Any ideas on repurposing it? Or about the functionality of the components?

Antique Radios

To add to the post on old TV's, its time for a post on old radios. There are two, an RCA Victor made out of Bakelite, and a mystery radio.
RCA victor radio:

Mystery Radio: Seen this before?

Old TV's

There's quite a few old TV's here, not sure on their age(s). There are two Zeniths and an RCA Victor.

Radio Equipment

There's a lot of radio equipment lying around, and there is a lot more buried somewhere. There's a gpr-90 reciever, a Collins 75a-1 reciever, and a Panasonic rf-4900.


A shelf of oscilloscopes have been gathering some serious dust. One or two of them are Heathkits. There's a couple old TV's, a vectorscope, and a multimeter or two (including a simpson), as well. Here's another close-up pic of a couple oscilloscopes:

Wednesday, June 18, 2008

Hewlett Packard 85

This is a picture of a functioning HP 85. The self-test runs, and basic programs run fine. No tape in the drive. It has 16k ram, and a .6mhz processor. Below is the back end , with a rom and a ram cartridge visible.