Remembering The MIT Radiation Laboratory

February 7, 2022 by Chris Lott 32 Comments

Back in the late 80s, our company managed to procure the complete 28 volume MIT Radiation Laboratory (Rad Lab) series, published in 1947, for the company library. To me, these books were interesting because I like history and old technology, but I didn’t understand why everyone was so excited about the acquisition. Only a cursory glimpse at the volumes would reveal that the “circuits” these books described used vacuum tubes and their “computers” were made from mechanical linkages. This was the 1980s, and we worked with modern radar and communications systems using semiconductors, integrated circuits, and digital computers. How could these old musty books possibly be of any practical use? To my surprise, it turned out that indeed they could, and eventually I came to appreciate the excitement. I even used several of them myself over the years.

Radiation Lab? Nuclear Radar?

In the years leading up to WW2, the idea of a civilian organization of scientists that would operate independently of the military and government bureaucracies was being championed by Dr. Vannevar Bush. The military and scientists had not worked well together during the first World War, and it looked like science and technology would be playing a much bigger role in the future.

It seemed certain that America would enter the conflict eventually, and Dr Bush and others believed that a new organizational framework was called for. To that end, the National Defense Research Committee (NDRC), which later became the Office of Scientific Research and Development (OSRD) was pitched to President Roosevelt and he approved it in June of 1940.

Almost immediately, a gift fell in the lap of the new organization — the Tizard Mission which arrived in the states from the UK in Sep 1940. They brought a literal treasure chest of technical innovations from the British, who hoped that US industry’s cooperation could help them survive what looked like certain and imminent invasion. One of those treasures was the cavity magnetron, which our own Dan Maloney wrote about a few years ago.

Within a few weeks, under the guidance of young Welshman “Taffy” Bowen, they had reviewed the design and gathered up the necessary equipment to fire it up. A 10 kV anode power supply and a 1,500 gauss electromagnet were procured, and the scientists gathered at the Bell Radio Laboratories in Whippany New Jersey on Sunday, Oct. 6, 1940. They powered up the cavity magnetron and were blown away by the results — over 10 kW of RF at 3 GHz (10 cm) from something the size of a bar of soap. Continue reading “Remembering The MIT Radiation Laboratory” →

Underwater Tanks Turn Energy Storage Upside-Down

February 2, 2022 by Lewin Day 129 Comments

Pumped hydro storage is one of the oldest grid storage technologies, and one of the most widely deployed, too. The concept is simple – use excess energy to pump a lot of water up high, then run it back through a turbine when you want to get the energy back later.

With the rise in renewable energy deployments around the world, there is much interest in finding ways to store energy from these often-intermittent sources. Traditional pumped hydro can help, but there is only so much suitable land to work with.

However, there could be a solution, and it lurks deep under the waves. Yes, we’re talking about underwater pumped hydro storage!

Continue reading “Underwater Tanks Turn Energy Storage Upside-Down” →

Save Money And Have Fun Using IEEE-488

January 31, 2022 by Chris Lott 32 Comments

A few months ago, I was discussing the control of GPIB equipment with a colleague. Based on only on my gut feeling and the briefest of research, I told him that the pricey and proprietary GPIB controller solutions could easily be replaced by open-source tools and Linux. In the many weeks that followed, I almost abandoned my stance several times out of frustration. With some perseverance, breaking the problems into bite-sized chunks, and lots of online searching to learn from other people’s experiences, my plan eventually succeeded. I haven’t abandoned my original stance entirely, I’ve taken a few steps back and added some qualifiers.

What is GPIB?

Example of HP-IB block diagram from the 1970s, from hp9845.net

Back in the 1960s, if test equipment was interconnected at all, there weren’t any agreed-upon methods for doing so. By the late 60s, the situation was made somewhat better by card-cage controller systems. These held a number of interface cards, one per instrument, presenting a common interface on the backplane. Although this approach was workable, the HP engineers realized they could significantly improve the concept to include these “bridging circuit boards” within the instruments and replacing the card cage backplane with passive cables. Thus began the development of what became the Hewlett-Packard Interface Bus (HP-IB). The October 1972 issue of the HP Journal introduced HP-IB with two main articles: A Practical Interface System for Electronic Instruments and A Common Digital Interface for Programmable Instruments: The Evolution of a System. Continue reading “Save Money And Have Fun Using IEEE-488” →

Shelf Actualization

January 28, 2022 by Al Williams 54 Comments

If you are old enough, you may remember that, for a time, almost every year was the year that home video was going to take off. Except it never was, until VHS tape machines appeared. We saw something similar with personal computers. Nowadays, we keep hearing about the home robot, but it never seems to fully materialize or catch on. If you think about it, it could be a problem of expectations.

What we all want is C3PO or Rosie the Robot that can do all the things we don’t want to do. What we usually get is something far less than that. You either get something hideously expensive that does a few tasks or something cheap that is little more than a toy.

Labrador Systems is trying to hit the middle ground. While no one would confuse their Caddie and Retriever robots with C3PO, they are useful but also simple, presumably to keep the cost down which are expected to cost about $1,500. The robots have been described as “self-driving shelves.” You can watch a video about the devices below.

Continue reading “Shelf Actualization” →

Strange Computer Languages: A Hacker’s Field Guide

January 26, 2022 by Al Williams 50 Comments

Why do we build radios or clocks when you can buy them? Why do we make LEDs blink for no apparent purpose? Why do we try to squeeze one extra frame out of our video cards? We don’t know why, but we do. That might be the same attitude most people would have when learning about esolangs — esoteric programming languages — we don’t know why people create them or use them, but they do.

We aren’t talking about mainstream languages that annoy people like Lisp, Forth, or VBA. We aren’t talking about older languages that seem cryptic today like APL or Prolog. We are talking about languages that are made to be… well… strange.

INTERCAL

We have to start at the beginning. INTERCAL. This was started as a joke in 1972 and the acronym is purportedly for Compiler Language With No Pronounceable Acronym. There was no actual implementation, though, until around 1990. Now there are two: C-INTERCAL and CLC-INTERCAL.

Since INTERCAL is a parody, it makes some very odd choices. For example, bitwise operators like AND operate with two arguments, but one of the arguments is reversed. That is, the top bit of one operand matches the bottom bit of the second operand. In a nod to social convention, there is a modifier known as PLEASE that you should sometimes use when, for example, reading data as in “PLEASE READ IN.” If you don’t use it often enough, the compile will fail warning you that the program is insufficiently polite. However, if you use it too often, you’ll also get an error that your program is excessively polite.

Originally, the implementation used EBCDIC, so it uses some characters that don’t appear on conventional 7-bit ASCII systems. This forced some character substitutions and now, with Unicode, some versions will allow the old-style characters if you prefer them. The INTERCAL manual renames nearly all the special characters for further confusion. A single quote is a “spark” and the equal sign is a “half-mesh”. Only the ampersand remains unscathed.

Want to know more? Be careful what you wish for.

Continue reading “Strange Computer Languages: A Hacker’s Field Guide” →

Would Nuclear Winter Cancel Out Global Warming?

January 25, 2022 by Lewin Day 79 Comments

Nuclear war was very much a front-of-mind issue during the fraught political climate of the Cold War era. Since then, atomic sabre rattling has been less frequent, though has never quite disappeared entirely.

Outside of the direct annihilation caused by nuclear war, however, is the threat of nuclear winter. The basic concept is simple: in the aftermath of a major nuclear war, the resulting atmospheric effects could lead to a rapid cooling in global temperatures.

Some say it couldn’t ever happen, while others – including Futurama – suggest with varying degrees of humor that it could help cancel out the effects of global warming. But what is the truth?

Hard data is isn’t really available, as thus far there have been no large-scale nuclear wars for scientists to measure. Several studies have explored the concept of nuclear winter, however, and explored its potential effects.

Continue reading “Would Nuclear Winter Cancel Out Global Warming?” →

Casually Chirping Into The World Of LoRaWAN

January 21, 2022 by Maya Posch 13 Comments

While wireless communications are unquestionably useful in projects, common wireless protocols such as WiFi and Bluetooth peter out after only a number of meters, which is annoying when your project is installed in the middle of nowhere. Moving to an LTE-based or similar mobile solution can help with the range, but this does not help when there’s poor cell coverage, and it tends to use more power. Fortunately, for low-bitrate, low-power wide-area networks (LPWAN) like e.g. sensor networks, there’s a common solution in the form of LoRaWAN, as in long-range wide area network (WAN).

The proprietary LoRa RF modulation technique that underlies LoRaWAN is based on Chirp Spread Spectrum (CSS). This modulation technique is highly resistant to channel noise and fading as well as Doppler shift, enabling it to transmit using relatively low power for long distances. LoRaWAN builds on top of the physical layer provided by LoRa to then create the protocol that devices can then use to communicate with other LoRa devices.

Courtesy of global LoRaWAN gateway and software providers such as The Things Industries and ThingSpeak, it’s possible even as a hobbyist to set up a LoRaWAN-powered sensor network with minimal cost. Let’s take take a look at exactly what is involved in setting up LoRaWAN devices, and what possible alternatives to LoRaWAN might be considered. Continue reading “Casually Chirping Into The World Of LoRaWAN” →