HP1973 Project Highlights Workings Of HP-45 Calculator

July 24, 2023 by 3 Comments

[Sarah K Marr] dabbles in retrocomputing and has a fascination with the Hewlett Packard HP-45 calculator, the second calculator in HP’s series introduced in 1973. Over a year ago, she wrote an HP-45 emulator for use on a terminal, dubbed HP45TERM. Not content with success, she upped the challenge and decided to build an even better emulator with a full-featured GUI written in Python. Oh, and she made it multi-platform as well. The result is the HP1973 project.

[Sarah] thought it would take just a few days, but it grew into a much bigger project, as often happens. We’re glad it did because the results are fantastic. The emulator gives you access not only to the calculator itself but can see everything under the hood. The emulator provides full ROM visibility, hardware registers, and standard debugging operations like single stepping. ROM images are available for the HP-45, the HP-35, and the HP-80. The GUI display is configurable, and there’s a plethora of help and information explaining the calculator’s internals. Pre-built binaries are available for MacOS, Windows, and Python source code (3.10.10+) for all operating systems (you’ll need to `pip install numpy` first). The emulation is faithful to the original calculator, and even the hidden timer function can be accessed.

Check this out if you’re into retro calculators. Our own Al Williams wrote about the history of the HP-35 back in 2018 if you want to learn more. Thanks to [J Peterson] for sending in the tip.

Weather In Wartime: The Importance Of British Meteorology In WWII

July 24, 2023 by 10 Comments

Weather can have a significant impact on transport and operations of all kinds, especially those at sea or in the air. This makes it a deeply important field of study, particularly in wartime. If you’re at all curious about how this kind of information was gathered and handled in the days before satellites and computer models, this write-up on WWII meteorology is sure to pique your interest.

Weather conditions were valuable data, and weather forecasts even more so. Both required data, which relied on human operators for instruments to be read and their readings transmitted.

The main method of learning weather conditions over the oceans is to persuade merchant ships to report their observations regularly. This is true even today, but these days we also have the benefit of things like satellite technology. Back in the mid-1900s there was no such thing, and the outbreak of WWII (including the classification of weather data as secret information due to its value) meant that new solutions were needed.

The aircraft of the Royal Air Force (RAF) were particularly in need of accurate data, and there was little to no understanding of the upper atmosphere at the time. Eventually, aircraft flew regular 10-hour sorties, logging detailed readings that served to provide data about weather conditions across the Atlantic. Readings were logged, encoded with one-time pad (OTP) encryption, then radioed back to base where charts would be created and updated every few hours.

The value of accurate data and precise understanding of conditions and how they could change was grimly illustrated in a disaster called the Night of the Big Wind (March 24-25, 1944). Forecasts predicted winds no stronger than 45 mph, but Allied bombers sent to Berlin were torn apart when they encountered winds in excess of 120 mph, leading to the loss of 72 aircraft.

The types of data recorded to monitor and model weather are nearly identical to those in modern weather stations. The main difference is that instruments used to be read and monitored by human beings, whereas today we can rely more on electronic readings and transmission that need no human intervention.

Superconducting Tape Leads To A Smaller Tokamak

July 23, 2023 by 80 Comments

Attempts to make a viable nuclear fusion reactor have on the whole been the domain of megabucks projects supported by countries or groups of countries, such as the European JET or newer ITER projects. This is not to say that smaller efforts aren’t capable of making their own advances, operations in both the USA and the UK are working on new reactors that use a novel superconducting tape to achieve a much smaller device.

The reactors in the works from both Oxfordshire-based Tokamak Energy and Massachusetts-based Commonwealth Fusion Systems, or CFS, are tokamaks, a Russian acronym describing a toroidal chamber in which a ring of high-temperature plasma is contained within a spiral magnetic field. Reactors such as JET or ITER are also tokamaks, and among the many challenges facing a tokamak designer is the stable creation and maintenance of that field. In this, the new tokamaks have an ace up their sleeve, in the form of a high-temperature superconducting tape from which those super-powerful magnets can be constructed. This makes the magnets easier to make, cheaper to maintain at their required temperature, and smaller than the low-temperature superconductors found in previous designs.

The world of nuclear fusion is a particularly exciting one to follow in these times of climate crisis, with competing approaches from laser-based devices racing with the tokamak projects to produce the research which will eventually lead to safer carbon-free power. If the CFS or Tokamak Energy reactors lead eventually to a fusion power station on the edge of our cities then it may just be some of the most important work we’ve ever reported.

Steel For Your Fighting Robot

July 23, 2023 by 8 Comments

The job of processing video after a large event must be a thankless one for whichever volunteer upon whose shoulders it falls, and thus it’s not unusual for talks at larger events to end up online much later than the event itself. Electromagnetic Field 2022 was last year, but they have continued to drop new videos. Among the latest batch is one from [Jennifer Herchenroeder], in which she discusses the steel used in her team’s BattleBot, Hijinx (Edit: her EMF talk was cut short due to time pressures, so she re-recorded it in full after the event and we’ve replaced the link. The EMF video meanwhile is here). The result is a fascinating introduction to the metallurgy of iron and steel, and is well worth a watch.

To fully understand the selection of armor steel it’s necessary to start from first principles with iron, to look at its various allotropes, and understand something of how those allotropes form and mix in the steel making and metalworking processes. We’re treated to a full description of the various tempering and hardening processes, before a panel-by-panel rundown of the various steels used by Hijinx.

For a Hackaday writer with a past in robot combat it’s fascinating to see how the design of robots has evolved over the decades since the British Robot Wars, and it’s particularly nice to see the current generation as part of our community. However, if you’ve tempted yourself, bear in mind that it’s not all plain sailing.

Continue reading “Steel For Your Fighting Robot” →

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Hackaday Links: July 23, 2023

July 23, 2023 by 4 Comments

It may be midwinter in Perth, but people still go to the beach there, which led to the surprising discovery earlier this week of what appears to be a large hunk of space debris. Local authorities quickly responded to reports of a barnacle-encrusted 2.5-m by 3-m tank-like object on the beach. The object, which has clearly seen better days, was described as being made of metal and a “wood-like material,” which on casual inspection is clearly a composite material like Kevlar fibers in some sort of resin. Local fire officials teamed up with forensic chemists to analyze the object for contamination; finding none, West Australia police cordoned off the device to keep the curious at bay. In an apparently acute case of not knowing how the Internet works, they also “urge[d] everyone to refrain from drawing conclusions” online, which of course sent the virtual sleuths into overdrive. An r/whatisthisthing thread makes a good case for it being part of the remains of the third stage of an Indian Polar Satellite Launch Vehicle (PSLV); reentry of these boosters is generally targeted at the East Indian Ocean for safe disposal, but wind and weather seem to have brought this artifact back from the depths.

Continue reading “Hackaday Links: July 23, 2023” →

VanMoof E-Bike Bankruptcy: The Risks Of Cloud-Connected Transport

July 23, 2023 by 66 Comments

When the bankruptcy of VanMoof, the company behind a series of e-bikes, was announced recently, many probably shrugged at this news. After all, what is an e-bike but a regular bicycle that has some electronics and a battery strapped to it to assist with cycling? Unfortunately for owners of a VanMoof e-bike, their fancy wheels come with a Bluetooth-connected smartphone app that somehow involves storing a special encryption key on the VanMoof servers, as detailed by [Gergely Orosz] at the Pragmatic Engineer. Without this key that is connected to your VanMoof account, your VanMoof app cannot communicate with your VanMoof e-bike.

Although basic functionality of the e-bike will be retained, features such as setting the gear modes, changing assistance mode, locking the bicycle and other features not exposed on the bicycle itself will be lost. Essentially this is the equivalent of losing the remote control to a modern-day TV and getting locked out of 90% of the device’s features.

Fortunately, as [Gergely] and others are (urgently) pointing out to VanMoof e-bike owners, this special key can be downloaded with a Key Exporter project on GitHub, as well as obtained and used with an alternative app by Cowboy Bikes, which is a competitor of VanMoof. The unfortunate reality remains, however, that should you lose this special key, you are going to be in a world of pain as your expensive e-bike now is mostly an e-brick.

(Thanks to [Jan Praegert] for the tip)

Amateur Estimates Of Venusian Day Using Arecibo Data

July 23, 2023 by 7 Comments

[Nathaniel Fairfield] aka [thandal] was curious about the actual rotation and axis tilt of Venus. He decided to spin up at GitHub Python repository to study the issue further, as one does. The scientific literature shows a wide range of estimates and variations for the planet’s rotation and axis tilt. He wondered if the real answer might be found in a publicly available set of uncalibrated delay-doppler images of Venus. These data were collected by the former Arecibo Observatory in Puerto Rico from 1988 through 2020.  [Thanda] observed that the planet’s rotation appears to be speeding up slightly, and furthermore, his estimates of the orbital axis were within 0.01 degrees of the International Astronomical Union’s (IAU) values. [Note: Venus is a bit confusing — one planetary rotation, 243 Earth days, is longer than its year, 225 Earth days].

Estimations of Venusian Orbital Period, [Thandal] Estimates in Green
Aligning and calibrating the raw data was no trivial task. You have to consider the radar’s (Earth’s) position and time, as well as Venus. Complicating the math even more, some times the radar was operated in a bistatic mode, with the Green Bank Telescope in West Virginia being the receiver.

There’s a lot of interesting signal processing going on here. The Doppler-delay data consists of images that are 8091×8092 array of complex values, has to be mapped onto the Venus geoid.  Then by using various surface features, one can compare their positions vs time and obtain an estimate of rotational speed and tilt. If these kinds of calculations interest you, be sure to check out [Thandal]’s summary report, and also take note of the poliastro Python astrodynamics library. Why is this important? One reason to better plan future missions.