The Transputer In Your Browser

April 4, 2025 by Al Williams 12 Comments

We remember when the transputer first appeared. Everyone “knew” that it was going to take over everything. Of course, it didn’t. But [Oscar Toledo G.] gives us a taste of what life could have been like with a JavaScript emulator for the transputer, you can try in your browser.

If you don’t recall, the transputer was a groundbreaking CPU architecture made for parallel processing. Instead of giant, powerful CPUs, the transputer had many simple CPUs and a way to chain them all together. Sounds great, but didn’t quite make it. However, you can see the transputer’s influence on CPUs even today.

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A Portable Electronics Workstation

April 4, 2025 by Al Williams 26 Comments

You don’t see them as often as you used to, but it used to be common to see “electronics trainers” which were usually a collection of components and simple equipment combined with a breadboard, often in a little suitcase. We think [Pro Maker_101’s] portable electronics workstation is in the same kind of spirit, and it looks pretty nice.

The device uses a 3D printed case and a custom PC board. There are a number of components, although no breadboard. There is a breakout board for Raspberry Pi GPIO, though. So you could use the screw terminals to connect to an external breadboard. We were thinking you could almost mount one as a sort of lid so it would open up like a book with the breadboard on one side and the electronics on the other. Maybe version two?

One thing we never saw on the old units? An HDMI flat-screen display! We doubt you’d make one exactly like this, of course, but that’s part of the charm. You can mix and match exactly what you want and make the prototyping station of your dreams. Throw in a small portable soldering iron, a handheld scopemeter, and you can hack anywhere.

We’d love to see something like this that was modular. Beats what you could build in 1974.

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Australia’s Silliac Computer

April 3, 2025 by Al Williams 17 Comments

When you think about the dawn of modern computers, you often think about the work done in the UK and the US. But Australia had an early computer scene, too, and [State of Electronics] has done a series of videos about the history of computers down under. The latest episode talks about SILLIAC, a computer similar to ILLIAC built for the University of Sydney in the late 1950s.

How many racks does your computer fill up? SILLIAC had quite a few.

This episode joins earlier episodes about CSIRAC, and WREDAC. The series starts with the CSIR Mark I, which was the first computer in the southern hemisphere.

The -AC computers have a long history. While you often hear statements like, “…in the old days, a computer like this would fill a room,” SILLIAC, in fact, filled three rooms. The three meters of cabinets were in one room, the power supply in another. The third room? Air conditioning. A lot of tubes (valves, in Australia at the time) generate a lot of heat.

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MIT Wants You To Secure Your Hardware Designs

April 3, 2025 by Al Williams 8 Comments

When you think of attacking or defending computer systems, you probably think of software viruses and the corresponding anti-virus software. But MIT’s 6.5950 class teaches secure hardware design — how to attack and defend CPUs from bad actors. Interested? The course is open source, so you can follow along as long as you don’t mind not getting a grade.

Browsing some of the lecture slides shows that the material isn’t as stuffy as you might imagine. A slide about side channel attacks, for example, features an article called “And Bomb the Anchovies,” which says that Washington DC pizza places know when big news is about to break because pizza delivery to places like the White House or the Pentagon trend upward (something spies call pizza-int, by the way).

Even if you don’t have a burning desire to design more secure hardware, some of the lecture slides make for an interesting flip through on a rainy weekend day. For example, the charts about RowHammer (“RowHammer in One Sentence”) is a great explanation about how software can cause DRAM failures to attack a computer. We only wished they’d identified companies A, B, and C in their study. There are also labs and they politely clarify what setup you need to do each lab (typically, just a Linux server, although some you can do with just a browser).

One of the great things about the Internet is that you can virtually audit classes from anywhere in the world, often for free. MIT is always up to something interesting.

The Magic Touch: A 555 Touch Switch

April 2, 2025 by Al Williams 14 Comments

There seems to be nothing a 555 can’t do. We’ve seen it before, but [electronzapdotcom] reminds us you can use a 555 and a few parts to make a reasonable touch switch in this video, embedded below.

The circuit uses some very large resistors so that noise from your body can overcome the logic level on the trigger and threshold inputs. You can easily adapt this idea if you need a simple touch switch. Though we imagine this circuit wouldn’t work well if you were in a quiet environment. We suspect 50 or 60 Hz hum is coupling through your finger and triggering the pins, but it could be a different effect.

How reliable is it? Beats us. The circuit is a bistable, so essentially your finger pumps a signal into a flip-flop. This is old trick, but could be useful. Of course, if you really need a touch switch, you have plenty of options. You can get little modules. Or, directly measure skin resistance.

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Zink Is Zero Ink — Sort Of

March 31, 2025 by Al Williams 37 Comments

When you think of printing on paper, you probably think of an ink jet or a laser printer. If you happen to think of a thermal printer, we bet you think of something like a receipt printer: fast and monochrome. But in the last few decades, there’s been a family of niche printers designed to print snapshots in color using thermal technology. Some of them are built into cameras and some are about the size of a chunky cell phone battery, but they all rely on a Polaroid-developed technology for doing high-definition color printing known as Zink — a portmanteau of zero ink.

For whatever reason, these printers aren’t a household name even though they’ve been around for a while. Yet, someone must be using them. You can buy printers and paper quite readily and relatively inexpensively. Recently, I saw an HP-branded Zink printer in action, and I wasn’t expecting much. But I was stunned at the picture quality. Sure, it can’t print a very large photo, but for little wallet-size snaps, it did a great job.

The Tech

Polaroid was well known for making photographic paper with color layers used in instant photography. In the 1990s, the company was looking for something new. The Zink paper was the result. The paper has three layers of amorphochromic dyes. Initially, the dye is colorless, but will take on a particular color based on temperature.

The key to understanding the process is that you can control the temperature that will trigger a color change. The top layer of the paper requires high heat to change. The printer uses a very short pulse, so that the top layer will turn yellow, but the heat won’t travel down past that top layer.

The middle layer — magenta — will change at a medium heat level. But to get that heat to the layer, the pulse has to be longer. The top layer, however, doesn’t care because it never gets to the temperature that will cause it to turn yellow.

The bottom layer is cyan. This dye is set to take the lowest temperature of all, but since the bottom heats up slowly, it takes an even longer pulse at the lower temperature. The top two layers, again, don’t matter since they won’t get hot enough to change. A researcher involved in the project likened the process to fried ice cream. You fry the coating at a high temperature for a short time to avoid melting the ice cream. Or you can wait, and the ice cream will melt without affecting the coating.

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Tiny Bubbles In The Memory

March 31, 2025 by Al Williams 16 Comments

We are always fascinated by bubble memory. In the late 1970s, this was the “Next Big Thing” that, as you may have guessed, was, in fact, not the next big thing at all. But there were a number of products that used it as non-volatile memory at a time when the alternative was tape or disk. [Smbakeryt] has a cool word processor with an acoustic coupler modem made by Teleram. Inside is — you guessed it — bubble memory.

The keyboard was nonfunctional, but fixable. Although we wouldn’t have guessed the problem. Bubble memory was quite high tech. It used magnetic domains circulating on a thin film of magnetic material. Under the influence of a driving field, the bubbles would march past a read-write head that could create, destroy, or read the state of the bubble.

Why didn’t it succeed? Well, hard drives got cheap and fairly rugged. The technology couldn’t compete with the high-density hard drives that could be reached with improved heads and recording strategies. Bubble memory did find use in high-vibration items, but also wound up in things like this terminal, at least one oscilloscope, and a video game.

Bubble memory evolved from twistor memory, one of several pre-disk technologies. While they are hard to come by today, you can find the occasional project that either uses some surplus or steals a part off of a device like this one.

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