Clover Computer: A Modern Z8000 CP/M Machine

August 21, 2022 by Chris Lott 20 Comments

Seeing some old Zilog 16-bit chips on eBay recently, [Scott Baker] was curious enough to snap them up and build himself a Z8000 computer. It started as a two-board solution, then he added a display module. Instead of layering the boards vertically à la a PC/104 stack, [Scott] decided to build them flat. His first backplane was triangular, but he opted for a square to accommodate one more expansion board in the future. The assembled contraption resembles a clover, hence the name Clover Computer.

The Z8000 was Zilog’s first 16-bit microprocessor, introduced in 1979. It was not hugely popular for a variety of reasons (the Z8000 Wikipedia article has some interesting details). The Z8000 was eclipsed in the marketplace by Intel’s 8088 and Motorola’s 32-bit 68000. One interesting point is that the Z8000 did not use microcode, and as a result, its transistor count was significantly less than its contemporaries. The Z8000 was used in some military applications, and despite its limited commercial success, it continued to be available from Zilog and licensed second sources up until 2012.

[Scott]’s design splits the system into a CPU board, a memory and serial board, and a display board. Along the way, he learns 1980’s era tricks from the Olivetti M20, one of the few computer systems designed around the Z8000. He also manages to find a recent Z8000 implementation of CP/M by GitHub user [4sun5bu], which [Scott] forked and adapted to his project (see project repo here). He succeeds in getting everything working, and ports a monitor, Tiny Basic, and Zork.

Check out his project write-up introductory link, and see it in action in the video below the break. Did you ever use or encounter the Z8000? Let us know in the comments!

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New OS For Commodore 64 Adds Modern Features

July 28, 2022 by Bryan Cockfield 43 Comments

The Commodore 64 was a revolutionary computer for its day and age. After four decades, though, it gets harder and harder to use these computers for anything more than educational or hobby electronics projects. [Gregory Nacu] is fiercly determined to challenge this idea, though, and has gone to great extremes to make this hardware still relevant in the modern age by writing a completely new operating system for the Commodore machines.

Known as C64OS, it squeezes everything it can out of the 8 bit processor and 64 kB of memory. The new OS includes switchable desktop workspaces, a windowing system, draggable icons, a Mac-style menu bar at the top, and drop-down menus for the icons (known as aliases in the demonstrations). The filesystem is largely revamped as well and enables a more modern directory system to be used. There are still some limitations like a screen resolution of 320×200 pixels and a fixed color palette which only allows for a handful of colors, but this OS might give Windows 3.1 a run for its money.

The project is still being actively developed but it has come a long way into a fairly usable state. It can be run on original hardware as well as long as you have a method of getting the image to the antique machine somehow. If not, the OS can likely run on any number of C64 emulators we’ve featured in the past.

Thanks to [Stephen] for the tip!

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Building A Serial Bus To Save An Old Hard Drive

June 28, 2022 by Bryan Cockfield 67 Comments

Universal Serial Bus has been the de facto standard for sending information to and from computer peripherals for almost two decades, but despite the word “universal” in the name this wasn’t always the case. Plenty of competing standards, including USB, existed in the computing world in the decades before it came to dominance, and if you’re trying to recover data from a computer without USB you might have to get creative with how it’s done.

[Ben] recently came across a 80486 with this problem, so he had to get creative to recover the contents of the drive. He calls it the “lunchbox” computer due to its form factor, and while it doesn’t have USB it does have a tried-and-trusted serial port to communicate with other computers. [Ben] wrote up a piece of software for both the receiving computer and the sending computer in order to copy the drive sectors one by one across a serial link to a standalone computer running Windows XP, and was able to recover the contents of the drive that way instead.

All of the code [Ben] wrote is available on his GitHub page for anyone looking to boot up a 30-year-old computer again. While it might sound uncommon, computers of this vintage are still around running things like CNC machines or old mainframes.

Faux-Retro “Tape” Player Runs On ESP32 And 80s Vibes

June 23, 2022 by Tom Nardi 31 Comments

At first glance, this gorgeous retro-styled audio player built by [Max Kern] could absolutely pass for the genuine article. But then you take a closer look and realize that the “tape” it’s playing is actually an animation running on a 320 x 240 IPS display, and the Play and Rewind buttons on the front aren’t the chunky electromechanical affairs of yesteryear but actually cleverly repurposed MX keyboard switches.

By now you’re probably realizing that this player is quite a bit smaller than you first imagined, which in turn, means that it even its case is a modern fabrication. While it might perfectly encapsulate the look and feel of a piece of 1980s consumer electronics, it was squirted out on a thoroughly modern desktop 3D printer.

Even so, [Max] made sure to include draft angles in the CAD design and and a distinctive separation line so the case looked like it was injection molded. Following similar logic, he decided against using a modern rechargeable battery pack to power the electronics, opting instead for a more era-appropriate set of AA batteries.

In terms of hardware, the custom PCB is home to an ESP32 WROOM, a MAX98357A I2S audio amplifier, a FT231XS USB-to-serial chip, with enough passives and regulators to keep them all well fed and happy. The ESP32 has more than enough computational horsepower to chew through MP3 files, which are conveniently loaded via an SD slot built into the side of the player. As the player was actually intended for audio books, onboard playback is limited to a mono speaker; though there is a 3.5 mm audio jack to plug in a pair of headphones for when the built-in speaker isn’t up to the task.

Check out the video after the break to see how the player is assembled, as well as a demonstration of its simple three-button user interface. It looks like a joy to use, though the lack of fast forward and rewind sound effects took us a bit by surprise given the otherwise impeccable attention to detail. We’ll assume there’s some technical limitation that makes this particularly difficult to implement, and that their absence is currently keeping [Max] up at night.

As impressive as the final product is, we can’t say it’s a surprise. Frankly, we wouldn’t expect anything less from [Max] at this point. His adaptive OLED macro pad wowed us back in 2020, and his ZeroBot is still one of the slickest designs for a DIY two-wheeled robots we’ve ever seen.

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Raspberry Pi Simulates The Real Analog TV Experience

June 20, 2022 by Dan Maloney 18 Comments

If you’ve laid hands on a retro analog TV, have the restoration bug, and you plan to make the final project at least somewhat period-correct, you face a bit of a conundrum: what are you going to watch? Sure, you can serve up just about any content digitally these days, but some programs just don’t feel right on an old TV. And even if you do get suitably retro programming, streaming isn’t quite the same as the experience of tuning your way through the somewhat meager selections as we did back in the analog days.

But don’t worry — this Raspberry Pi TV simulator can make your streaming experience just like the analog TV experience of yore. It comes to us from [Rodrigo], who found a slightly abused 5″ black-and-white portable TV that was just right for the modification. The battery compartment underneath the set made the perfect place to mount a Pi, which takes care of streaming a variety of old movies and shorts. The position of the original tuning potentiometer is read by an Arduino, which tells the Pi which “channel” you’re currently tuned to.

Composite video is fed from the Pi’s output right into the TV’s video input, and the image quality is just about what you’d expect. But for our money, the thing that really sells this is the use of a relay to switch the TV’s tuner back into the circuit for a short bit between channel changes. This gives a realistic burst of static and snow, just like we endured in the old days. Hats off to [Rodrigo] for capturing everything that was awful about TV back in the day — Mesa of Lost Women, indeed! — but still managing to make it look good.

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Framework Board Gets This Round Display PC Rolling

May 10, 2022 by Tom Nardi 15 Comments

The Framework laptop is already a very exciting prospect for folks like us — a high-end computer that we can actually customize, upgrade, and repair with the manufacturer’s blessing? Sounds like music to our ears. But we’re also very excited about seeing how the community can press the modular components of the Framework into service outside of the laptop itself.

A case in point, this absolutely gorgeous retro-inspired computer built by [Penk Chen]. The Mainboard Terminal combines a Framework motherboard, five inch 1080 x 1080 round LCD display, and OLKB Preonic mechanical keyboard into a slick 3D printed enclosure that’s held together with magnets for easy access. Compared to the Raspberry Pi that we usually find tucked into custom computer builds like this, the Framework board offers incredible performance, not to mention the ability to run x86 operating systems and software.

[Penk] has Ubuntu 22.04 LTS loaded up right now, and he reports that everything works as expected, though there are a few xrandr commands you’ll need to run in order for the system to work properly with the circular display. The standard Ubuntu UI doesn’t look particularly well suited to such an unusual viewport, but we imagine that’s an issue you’ll have to learn to live with when experimenting with such an oddball screen.

It was just a few weeks ago that we brought you word that Framework was releasing the mechanical drawings for their Mainboard module, and we predicted then that it would be a huge boon to those building bespoke computers. Truth be told we expected a cyberdeck build of some sort to be the first one to hit our inbox, but you certainly won’t catch us complaining about seeing more faux-vintage personal terminals.

Verbot Goes To The Dark Side

May 9, 2022 by Adam Fabio 14 Comments

What happens to old, neglected 1980s toy robots? According to the [Randi Rain], they turn to the dark side! Way back in the ’80s, Tomy had an entire line of robots — from keychain wind-up toys to rolling, talking machines almost 2 feet tall. Tucked into the middle of this line was Verbot. Verbot’s claim to fame is that it is a voice-controlled robot. More than that, it was speaker-dependent. Train the robot with commands like “go forward” and then watch as it responds to your every command.

As you might guess, the speech recognition wasn’t great by today’s standards. Recognition was handled by a Microcontroller — a Mitsubishi product that was possibly a mask programmed 8051 variant. Pretty novel for an 80s toy — in fact, there’s a patent for it.

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