Kim-1: Memory Problem Resolved

July 10, 2023 by 20 Comments

At the very start of the personal computer revolution, there were relatively inexpensive boards with little more than a CPU, some memory, a display, and switches or a keypad. Some of these had expansion ports meant to allow you to build up, and some were just “trainers” to learn about computers. While you could argue that the Altair fell into this category, it had a case and a proper bus. The computers we are thinking about were usually just on a single board and — with luck — had an edge connector for expansion. Perhaps the most famous of these was the KIM-1 and [Old VCR] shows us how he brought one back to life.

These were highly popular mainly because of the low price of $245 back in 1976. For that price you got a calculator-style keyboard and LED display, 1K of RAM, and 2K of ROM. [Old VCR] has several and noticed that one was developing memory problems.

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The ThinkPad You All Wish You Had, With A Brain That’s Not Ancient

July 10, 2023 by 26 Comments

An IBM (or, later, Lenovo) ThinkPad is a popular choice in our community. They’re prized for their rugged design, longevity, and good software support. Over the many years that the line has been available, there have been a few models which have captured the attention more than others, and among those, probably the most sought-after is the ThinkPad 701c. It would be an unremarkable mid-1990s 486 laptop were it not for the party piece of that flip-out butterfly keyboard (see video, below). [Karl Buchka] has one that’s profoundly dead, and rather than use it as a novelty paperweight, he’s giving it a new lease of life with a Framework motherboard.

This is very much a work in progress, so there will be plenty more to come, but so far, he’s taken the display panel from an iPad and made it work with the Framework board, and designed an entirely new lower case for the Thinkpad. This will hold the Framework board with its USB-C ports at the edge, so in the place of its USB-based expansion modules, he’s made a custom external port replicator. Meanwhile, a Teensy handles that unique keyboard. We’re told that the design files will all eventually be put online should anyone else want to try.

We’d normally be slightly upset were someone to butcher something as unusual as a 701c, however, in thic ase we can see that it turns a broken computer into one that should see quite a bit of use.  We can’t help envying him this project.

Understandably not many 701c owners have dived inside their machines, but we have previously brought you a contemporary processor upgrade. If you’ve never seen the 701c’s keyboard — or you just want to see it again — here you go:

Thanks [Ł. Juszczak] for the tip.

Enhance VR Immersion By Shoehorning An Ambilight Into A Headset

July 9, 2023 by 6 Comments

Everyone wants a wider field of view in their VR headsets, but that’s not an easy nut to crack. [Statonwest] shows there’s a way to get at least some of the immersion benefits with a bit of simple hardware thanks to the VR Ambilight.

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A Quick Look At The Hilbert Transform

July 9, 2023 by 30 Comments

While the Fourier transform gets all the attention, there are other transforms that engineers and mathematicians use to transform signals from one form to another. Sometimes you use a transform to make a signal more amenable to analysis. Other times, you do it because you want to manipulate it, and the transform is easier to change than the original signal. [Electroagenda] explains the Hilbert transform, which is often used to generate single-sideband signals.

The math behind the transformation is pretty hairy. However, if you understand the Fourier transformer, you can multiply the Fourier transform by -i sgn(ω), but that isn’t really going to help you much in a practical sense. If you don’t want to bog down in the math, skip immediately to section two of the post. That’s where it focuses more on the practical effect of the transform. You can think of the transform as a function that produces a 90 degree phase shift with a constant gain. For negative frequencies, the rotation is 90 degrees and for positive frequencies, the shift is negative.

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Hackaday Links: July 9, 2023

July 9, 2023 by 8 Comments

Good news this week from Mars, where Ingenuity finally managed to check in with its controllers after a long silence. The plucky helicopter went silent just after nailing the landing on its 52nd flight back on April 26, and hasn’t been heard from since. Mission planners speculated that Ingenuity, which needs to link to the Perseverance rover to transmit its data, landed in a place where terrain features were blocking line-of-sight between the two. So they weren’t overly concerned about the blackout, but still, one likes to keep in touch with such an irreplaceable asset. The silence was broken last week when Perseverance finally made it to higher ground, allowing the helicopter to link up and dump the data from the last flight. The goal going forward is to keep Ingenuity moving ahead of the rover, acting as a scout for interesting places to explore, which makes it possible that we’ll see more comms blackouts. Ingenuity may be more than ten-fold over the number of flights that were planned, but that doesn’t mean it’s ready for retirement quite yet.

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Reviving Interlisp With The Medley Interlisp Project

July 9, 2023 by 21 Comments

Within the Artificial Intelligence and natural language research communities, Lisp has played a major role since 1960. Over the years since its introduction, various development environments have been created that sought to make using Lisp as easy and powerful as possible. One of these environments is Interlisp, which saw its first release in 1968, and its last official release in 1992. That release was Medley 2.0, which targeted various UNIX machines, DOS 4.0, and the Xerox 1186. Courtesy of the Interlisp open source project (GitHub), Medley Interlisp is available for all to use, even on modern systems.

The documentation contains information on how to install Medley on Linux but also Mac and Windows (via WSL1 or WSL2). For those just curious to give things a swing, there’s also an online version you can log into remotely. What Medley Interlisp gets you is an (X-based) GUI environment in which you can program in Lisp, essentially an IDE with a debugger and the (in)famous auto-correction tool for simple errors such as typos, known as the DWIM (Do What I Mean), which much like the derived version in Emacs seeks to automatically fix simple issues like misspellings without forcing the developer to fix it and restart the compilation.

Thanks to [Pixel_Outlaw] for the tip and for also telling us about a project they wrote using Medley Interlisp for the Spring Lisp Game Jame 2023 titled Interlisp Fifteen Puzzle.

Miniware TS1C: A Cordless Soldering Iron With A Station

July 9, 2023 by 19 Comments

Most soldering irons in the market seem to fall into a few distinct categories. They either provide a full-blown station to which the soldering iron is wired, powered straight by mains, or an iron powered by DC power. The Miniware TS1C takes up an interesting position here in that it features both a station you put the iron into and adjust the temperature, as well as a fully cordless iron. Sounds too good to be true, perhaps, but a recent Tom’s Hardware review by [Les Pounder] seems to think it has real merit.

Behind the glossy exterior and marketing, we find a cordless soldering iron that uses a supercapacitor to power itself when it is not inserted into the station, with communication between the iron and station performed using Bluetooth. This way, you can keep an eye on both the tip temperature and the remaining charge left, which [Les] found to be sufficient for soldering about 80 smaller joints, with the marketing claiming it can solder 180 size 0805 SMD parts with one charge.

The advantage of having a station is that it is the part that is wired to a power bank or wall wart, with the temperature setting performed using a chunky dial. The station also provides a place for the iron in between soldering sessions, but in order to recharge the iron, the brass bands near the front have to be pushed into the holder for them to make contact. This also makes one-handed removal of the iron from the holder not as easy as you’d hope.

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