Protoboard Z80 Computer Teaches The Basics

As curious people, we’re all incredibly fortunate to live in an age where information can so easily be obtained. If you want to learn how something works, from a cotton gin to an RBMK reactor, you’re just a few keystrokes away from articles, diagrams, and videos on the subject. But as helpful as all of that information can be, we also know that there’s no substitute for hands-on experience.

While we can’t recommend you try building a miniature graphite-moderated nuclear reactor, there’s plenty of other devices that you can study by constructing your own functioning model. For example, when [Jorisclayton] wanted to really know what was going on inside a computer, they decided to go back to basics and build their own Z80 machine. To maximize the experience, they skipped any of the existing kit designs and instead wired the whole thing up by hand across a few perfboards.

The main board contains a 4 MHz Z80 processor, paired with 32K ROM and 64K RAM. Here you’ll also find the clock generator, I/O decoder, serial port, voltage regulator, and a trio of expansion slots that use a long strip of 2.54 mm pin headers as the interface. In the first expansion slot you’ve got a primordial “graphics card” based around the TMS9918 video display controller (VDC) and 16K of additional RAM. The second expansion card has a CompactFlash reader and an LED array mapped to I/O address 0x00h so it can be used for various notifications.

[Jorisclayton] says the final expansion board is still being worked on, but the idea is for it to handle user input through a PS/2 keyboard connector, as well as provide ports for a pair of Super Nintendo (or compatible) controllers. Everything is held together with a minimalist 3D printed frame to show off all that careful soldering.

Obviously there’s no PCB design files to share for this one, but [Jorisclayton] has posted a schematic for wiring everything up if you’re looking for resources to build your own Z80 computer. Sure the chips themselves might no longer be in production, but that doesn’t mean this venerable CPU is going anywhere just yet.

An Umbrella Can Teach A Thing Or Two About Product Longevity

This time of year always brings a few gems from outside Hackaday’s usual circle, as students attending industrial design colleges release their final year projects, The worlds of art and engineering sit very close together at times, and theirs is a discipline which sits firmly astride that line. This is amply demonstrated by the work of [Charlie Humble-Thomas], who has taken an everyday object, the umbrella, and used it to pose the question: How long should objects last?

He explores the topic by making three different umbrellas, none of which we are guessing resemble those you could buy. The first is not particularly durable but is completely recyclable, the second is designed entirely with repairability in mind, while the third is hugely over-engineered and designed for durability. In each case the reader is intended to think about the impact of the umbrella before them.

What strikes us is how much better designed each one is than the typical cheap umbrella on sale today, with the polypropylene recyclable one being flimsy by design, but with a simplicity missing from its commercial counterpart. The durable one meanwhile is full of CNC parts, and carbon fiber.

If you’re hungry for more student work in this vein, we recently brought you this toasty typewriter.

Kaffa Roastery founder Svante Hampf shows a bag of their AI-conic coffee blend.

AI-Created Coffee Blend Isn’t Terrible

Weren’t we just talking about coffee-based sacrilege the other day? Here’s something to make the single-origin bean snobs chew their espresso cups: an artisan roastery in Helsinki is offering a coffee blend created by artificial intelligence called AI-conic. The idea, of course, is that technology will lighten the workload needed to produce coffee.

This is an interesting development because Finland consumes the most coffee in the world, according to the International Coffee Organization. Coffee roasting is a highly-valued traditional artisan profession there, so it stands to reason that they might turn to technology for help.

Just like with scotch whisky, there’s nothing wrong with coffee blends outright. Bean blends are good for consistency, when you want every cup to taste pretty much exactly the same. Single-origin beans, though, are traceable to one location, and as a result, they usually have a distinct flavor based on the climate they’re grown in.

If you’re new to coffee, blends are a nice, safe way to start out. And, interestingly, the AI chose to make the blend out of four different types of beans instead of the usual two or three, despite being tasked with creating a blend that would suit the palates of coffee enthusiasts. But the coffee experts agreed that the AI blend was “perfect” and needed no human intervention. We probably won’t be getting to Finland anytime soon, so if you try it, let us know how it tastes!

Do you like cold brew? How would you like to be able to brew some in just three minutes?

A DIY split-flap clock in red, black, and white.

Split-Flap Clock Uses Magnets Everywhere

While split-flap alarm clocks once adorned heavy wood nightstands in strong numbers, today the displays are most commonly found in train stations and airports. Hey, at least they’re still around, right? Like many of us, [The Wrench] has always wanted to make one for themselves, but they actually got around to doing it.

A DIY split-flap clock and its magnetic base.This doesn’t seem like a beginner-friendly project, but [The Wrench] says they were a novice in 3D design and so used Tinkercad to design all the parts. After so many failures, they settled on a design for each unit that uses a spool to attach the flaps, which is turned by a stepper motor.

A small neodymium magnet embedded in the primary gear and a Hall effect sensor determine where the stepper motor is, and in turn, which number is displayed. Everything is handled by an Arduino Nano on a custom PCB.

Aside from the sleek, minimalist look, our favorite part is that [The Wrench] used even more magnets to connect each display segment to the base. You may have noticed that there are only three segments, because the hours are handled by a single display that has flaps for 10, 11, and 12. This makes things simpler and gives the clock an interesting look. Be sure to check out the build video after the break.

Want to build a more complicated clock? Try suspending sand digits in the air with persistence of vision.

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DIY Bimetallic Strip Dings For Teatime

Do you like your cup of tea to be cooled down to exactly 54 C, have a love for machining, and possess more than a little bit of a mad inventor bent? If so, then you have a lot in common with [Chronova Engineering]. In this video, we see him making a fully mechanical chime-ringing tea-temperature indicator – something we’d be tempted to do in silicon, but that’s admittedly pedestrian in comparison.

The (long) video starts off with making a DIY bimetallic strip out of titanium and brass, which it pretty fun. After some math, it is tested in a cup of hot water to ballpark the deflection. Fast-forward through twenty minutes of machining, and you get to the reveal: a tippy cup that drops a bearing onto a bell when the deflection backs off enough to indicate that the set temperature has been reached. Rube Goldberg would have been proud.

OK, so this is bonkers enough. But would you believe a bimetallic strip can be used as a voltage regulator? How many other wacky uses for this niche tech do you know?

Thanks [Itay] for the tip!

The 3D Printed Computer Space Takes Shape

A few weeks ago we brought you news of a project to recreate the flowing lines of the first computerised arcade game, Computer Space, as a full-size 3D printed replica. We left the project with all the parts put together to make a complete but unfinished shell that was very recognizable as a Computer Space cabinet but had neither finishing nor internals. Now we’re very pleased to bring you the conclusion of the project, as it moves from unfinished 3D print to playable cabinet.

The video below the break is a journey of print finishing to a very high standard with that lustrous blue glitter resin, but oddly it’s most interesting to find out about the manufacturing quirks of the original. How the rear door was imprecisely cut from plywood and fixed on with gate hinges, how the ventilation holes differ from cabinet to cabinet, and how the collection vessel for those quarters was an old tin. The monitor is a newer broadcast CRT in this version and the electronics are naturally  modern, but if you didn’t know, you’d be hard pressed to spot that you weren’t playing the real thing.

Finally we see the gameplay which is admittedly frustrating, and a little bit of punditry as to why this wasn’t the commercial success of the following Pong. It’s a fascinating look at the early computer game industry.

Have a look at our coverage of the first episode of this project.

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Hackaday Podcast Episode 270: A Cluster Of Microcontrollers, A Rocket Engine From Scratch, And A Look Inside Voyager

Join Hackaday Editors Elliot Williams and Tom Nardi as they get excited over the pocket-sized possibilities of the recently announced 2024 Business Card Challenge, and once again discuss their picks for the most interesting stories and hacks from the last week. There’s cheap microcontrollers in highly parallel applications, a library that can easily unlock the world of Bluetooth input devices in your next project, some gorgeous custom flight simulator buttons that would class up any front panel, and an incredible behind the scenes look at how a New Space company designs a rocket engine from the ground up.

Stick around to hear about the latest 3D printed gadget that all the cool kids are fidgeting around with, a brain-computer interface development board for the Arduino, and a WWII-era lesson on how NOT to use hand tools. Finally, learn how veteran Hackaday writer Dan Maloney might have inadvertently kicked off a community effort to digitize rare documentation for NASA’s Voyager spacecraft.

Check out the links below if you want to follow along, and as always, tell us what you think about this episode in the comments!

Download your very own copy of the podcast right about here.

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