All Projections Suck, So Play Risk On A Globe Instead

The worst thing about the getting people together is when everyone starts fighting over their favourite map projection– maybe you like the Watterman Butterfly, but your cousin really digs Gall-Peters, and that one Uncle who insists on defending Mercator after a couple of beers. Over on Instructables [madkins9] has an answer to that problem that will still let you play a rousing game of Risk– which will surely not drag on into the night and cause further drama– skip the projection, and put the game on a globe. 

The pieces are from a 1960s version. The abstract tokens have a certain charm the modern ones lack.

Most globes, being cardboard, aren’t amenable to having game pieces cling to them. [madkins9] thus fabricates a steel globe from a pair of pre-purchased hemispheres. Magnets firmly affixed to the bases of all game pieces allow them to stick firmly to the spherical play surface. In a “learn from my mistakes” moment, [madkins] suggests that if you use two pre-made hemispheres, as he did, you make sure they balance before welding and painting them.

While those of us with less artistic flair might be tempted to try something like a giant eggbot, [madkins] was able to transfer the Risk world map onto his globe by hand. Many coats of urethane mean it should be well protected from the clicking or sliding magnet pieces, no matter how long the game lasts. In another teachable moment, he suggests not using that sealer over sharpie. Good to know.

Once gameplay is finished, the wooden globe stand doubles as a handsome base to hold all the cards and pieces until the next time you want to end friendships over imaginary world domination. Perhaps try a friendly game of Settlers of Catan instead. 

Schematic for the TULIP4041

TULIP: The Ultimate Intelligent Peripheral For The HP-41 Handheld Calculator

[Andrew Menadue] wrote in to let us know about the TULIP-DevBoard and TULIP-Module being developed on GitHub.

TULIP is short for “The Ultimate Intelligent Peripheral” and it’s an everything expansion board for the HP-41 line of handheld calculators sold by HP from 1979 to 1990. These particular calculators support Reverse Polish notation which seems to be one of those things, like the Dvorak keyboard, where once you get used to it you can never go back.

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Xcc700: Self-Hosted C Compiler For The ESP32/Xtensa

With two cores at 240 MHz and about 8.5 MB of non-banked RAM if you’re using the right ESP32-S3 version, this MCU seems at least in terms of specifications to be quite the mini PC. Obviously this means that it should be capable of self-hosting its compiler, which is exactly what [Valentyn Danylchuk] did with the xcc700 C compiler project.

Targeting the Xtensa Lx7 ISA of the ESP32-S3, this is a minimal C compiler that outputs relocatable ELF binaries. These binaries can subsequently be run with for example the ESP-IDF-based elf_loader component. Obviously, this is best done on an ESP32 platform that has PSRAM, unless your binary fits within the few hundred kB that’s left after all the housekeeping and communication stacks are loaded.

The xcc700 compiler is currently very minimalistic, omitting more complex loop types as well as long and floating point types, for starters. There’s no optimization of the final code either, but considering that it’s 700 lines of code just for a PoC, there seems to be still plenty of room for improvement.

refurbished baby blue vice next to its refurbisher

Vice Of Old Brought To The Modern Age

People say they don’t make em’ like they used to, and while this isn’t always the case, it’s certainly true that old vices rarely die with time. This doesn’t mean they can’t use a refresh. [Marius Hornberger] recently backed that up when he decided to restore an old vice that had seen better days.

custom bearing and rod
Customized axial bearing assembly

When refreshing old tools, you’ll almost always start the same: cleaning up all the layers of grease and ruined paint. The stories that each layer could tell will never be known, but new ones will be made with the care put into it by [Marius]. Bearings for the tightening mechanism had become worn down past saving, requiring new replacements. However, simply swapping them with carbon copies would be no fun.

[Marius] decided to completely rethink the clamping mechanism, allowing for much smoother use. To do this was simple, just machine down new axial bearings, design and print a bearing cage, machine the main rod itself, and finally make a casing. It’s simple really, but he wasn’t done and decided to create a custom torque rod to hammer in his vicing abilities. Importantly, the final finish was done by spraying paint and applying new grease.

Old tools can often be given new life, and we are far from strangers to this concept at Hackaday. Make sure to check out some antique rotary tools from companies before Dremel!

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Linux Fu: Compose Yourself!

Our computers can display an astonishing range of symbols. Unicode alone defines more than 150,000 characters, covering everything from mathematical operators and phonetic alphabets to emoji and obscure historical scripts. Our keyboards, on the other hand, remain stubbornly limited to a few dozen keys.

On Windows, the traditional workaround involves memorizing numeric codes or digging through character maps. Linux, being Linux, offers something far more flexible: XCompose. It’s one of those powerful, quietly brilliant features that’s been around forever, works almost everywhere, and somehow still feels like a secret.

XCompose is part of the X11 input system. It lets you define compose sequences: short key sequences that produce a Unicode character. Think of it as a programmable “dead key” system on steroids. This can be as simple as programming an ‘E’ to produce a Euro sign or as complex as converting “flower” into a little flower emoji. Even though the system originated with X11, I’ve been told that it mostly works with Wayland, too. So let’s look deeper.

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The Confusing World Of Bus Mice

The USB port which first appeared on our computers some time in the mid-1990s has made interfacing peripherals an easy task, save for the occasional upside down connector. But in the days before USB there were a plethora of plugs and sockets for peripherals, often requiring their own expansion card. Among these were mice, and [Robert Smallshire] is here with a potted history of the many incompatible standards which confuse the retrocomputing enthusiast to this day.

The first widely available mice in the 1980s used a quadrature interface, in which the output from mechanical encoders coupled to the mouse ball is fed directly to the computer interface which contains some form of hardware or microcontroller decoder. These were gradually superseded by serial mice that used an RS-232 port, then PS/2 mice, and finally the USB variant you probably use today.

Among those quadrature mice — or bus mice, as early Microsoft marketing referred to them — were an annoying variety of interfaces. Microsoft, Commodore, and Atari mice are similar electrically and have the same 9-pin D connector, yet remain incompatible with each other. The write-up takes a dive into the interface cards, where we find the familiar 8255 I/O port at play. We’d quite like to have heard about the Sun optical mice with their special mouse pad too, but perhaps their omission illustrates the breadth of the bus mouse world.

This piece has certainly broadened our knowledge of quadrature mice, and we used a few of them back in the day. If you only have a USB mouse and your computer expects one of these rarities, don’t worry, there’s an adapter for that.

Know Audio: Microphone Basics

A friend of mine is producing a series of HOWTO videos for an open source project, and discovered that he needed a better microphone than the one built into his laptop.  Upon searching, he was faced with a bewildering array of peripherals aimed at would-be podcasters, influencers, and content creators, many of which appeared to be well-packaged versions of very cheap genericised items such as you can find on AliExpress.

If an experienced electronic engineer finds himself baffled when buying a microphone, what chance does a less-informed member of the public have! It’s time to shed some light on the matter, and to move for the first time in this series from the playback into the recording half of the audio world. Let’s consider the microphone.

Background, History, and Principles

A microphone is simply a device for converting the pressure variations in the air created by sounds, into electrical impulses that can be recorded. They will always be accompanied by some kind of signal conditioning preamplifier, but in this instance we’re considering the physical microphone itself. There are a variety of different types of microphone in use, and after a short look at microphone history and a discussion of what makes a good microphone, we’ll consider a few of them in detail. Continue reading “Know Audio: Microphone Basics”