Retro Computers From Paper

Want to start your own collection of retro computers, for free? Well graphic designer [Rocky Bergen]’s collection of paper craft models might be the answer. [Rocky] has designed over a dozen models of old computers, including classics such as the IMSAI 8080, Commodore Pet, and the BBC Microcomputer to name just a few.

The completed size of these models isn’t mentioned, but inspecting the PDF file of a randomly selected Commodore C64 model shows it was intended to be printed on A3 paper ( 297 x 420 mm, or roughly the size of an 11 x 17 ANSI C page if you think better in inches ). That still doesn’t give us the finished size of a model, but one collector posted on [Rocky]’s site that when he scaled it to A4 paper, the resulting computer was a perfect match for use with common 1/6 scale dolls and dollhouses (also known as playscale). Of course, the pattern existing as a computer PDF file, you can scale it to any size you want.

We’ve covered a few paper craft projects in the past, including these cool automata, a claw from a crane game, and even a gyroscope that really spins. Check out the video below the break to see [Rocky] assembling the Apple II paper craft model. Thanks to [CollegeCop] for sending this into our tip line.

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Pi Pico-Powered ATX Motherboard

For a couple of years, embedded developer and Rust addict [Jonathan Pallant] aka [theJPster] has been working on a simple computer which he calls the Neotron. The idea is to make a computer that is not only easy to use but easy to understand as well. He describes it as a CP/M- or DOS-like operating system for small ARM microcontrollers. His most recent project is powered by a Raspberry Pi RP2040 Pico and built in the format of a microATX motherboard. This board packs a lot of features for a Pico-based design, including 12-bit color VGA and seven expansion slots. See his GitHub repository for a full list of specifications, and all the files needed to build your own — it is an Open Source project after all.

Besides the Neotron Pico itself, a couple of gems caught our eye in this well-documented project. [theJPster] was running out of I/O pins on the Pico, and didn’t have enough left over for all the peripherals’ chip selects. Check out how he uses an MCP23S17 SPI-bus I/O expander and a tri-state buffer to solve the problem.

On a more meta level, we are intrigued by his use of GitHub Actions. Per the standard concept of repositories, they shouldn’t contain the results of a build, be that an executable binary or Gerber files. Distribution of the build products is typically handled outside of GitHub, using something like GitHub’s Large File Storage service, or just ignoring convention altogether and putting them in the repo anyway. [theJPster] uses another method, employing GitHub Actions to generate the files needed for PCB fabrication, for example.

The Neotron Pico is the latest in a series of boards made to run Neotron OS. Previous boards include:

  • Neotron 9x — Microchip SAM9X
  • Neotron 1000 — STM32H7 + Lattice Semi iCE40 FPGA
  • Neotron 600 — Teensy 4.1
  • Neotron 340ST — ST 32F746G-DISCOVERY

Repairing A Vintage HP 9825 The Hard Way

[CuriousMarc] is at it again, this time trying to undo the damage from a poorly designed power circuit, that fried the internals of his HP 9825 computer. (Video, embedded below.)

The power supply on this particular model has a failure mode where a dying transistor can lead to 13 V on the 5 V line. This causes all the havoc one would expect on the internals of a 1970s era portable computer. This particular computer is rather rare, so instead of calling it a lost cause, our protagonist decides to replace the faulty transistor, install a proper overvoltage protection circuit, and then start the tedious hunt for which chips actually let their magic smoke out.
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Homebrew 68K Micro-ATX Computer Runs Its Own OS

We’re no stranger to home built Motorola 68000 computers here at Hackaday, but more often than not, they tend to be an experiment in retro minimalism. The venerable processor is usually joined by only a handful of components, and there’s an excellent chance they’ll have taken up residence on a piece of perfboard. Then [NotArtyom] sent in his Blitz, and launched the bar into the stratosphere.

Make no mistake, the Blitz isn’t just some simple demo of classic chips. The open hardware motherboard has onboard floppy, IDE, and PS/2 interfaces, with a trio of 8-bit ISA expansion slots for good measure. The  Motorola 68030 CPU is humming along at 50 MHz, with 4 MB of RAM and 512 KB of ROM along for the ride. Designed to fit the Micro-ATX motherboard standard, you can even mount the Blitz in a contemporary PC case and run it on a standard ATX power supply.

An earlier prototype of the Blitz motherboard.

As if the hardware wasn’t impressive enough, [NotArtyom] went ahead and created his own open source DOS-like operating system for it to run. Written in portable C, G-DOS can run on various m68k boards as well as ARM and PowerPC machines. It’s an incredible project in its own right. If you’re looking for something to show off your homebrew computer, you could certainly do worse than pulling down a copy of G-DOS. If you do port it to a new board, make sure to let [NotArtyom] know.

It’s taken [NotArtyom] three years to develop Blitz and G-DOS with his only goal being to better understand homebrew computers. He has no interest in monetizing the design or turning it into a kit, but instead hopes it will be a resource and inspiration for others with similar interests. Oh yeah, and he did all of this before he even graduated high school. If you weren’t questioning your life’s accomplishments before, now would be a great time to start.

Interested in building your own Motorola 68000 computer, but haven’t yet attained the wizarding level of [NotArtyom]? You could start with something a bit simpler like the 68k-nano, or if you’re really in a pinch, just dead bug a Dragonball 68328.

MouSTer Brings USB To Retro Computers

Folks who like the take the old Amiga out for the occasional Sunday drive usually do it because they have wistful memories of the simpler times. Back when you could edit documents or view spreadsheets on a machine that had RAM measured in kilobytes instead of gigabytes. But even the most ardent retro computer aficionado usually allows for a bit of modern convenience.

Enter the mouSTer. This tiny device converts a common USB HID mouse into something older computers can understand. It even supports using Sony’s PlayStation 4 controller as a generic game pad. While the firmware is still getting tweaked, the team has confirmed its working on several classic machines and believe it should work on many more. Considering the prices that some of these old peripherals command on the second hand market, using a USB mouse or controller on your vintage computer isn’t just more convenient, but will likely be a lot cheaper.

Confirmed retrocomputing superfan [Drygol] is a member of the team working on mouSTer, and in a recent post to his retrohax blog, he talks a bit about what’s happened since his last update over the summer. He also talks a bit about the challenges they’ve faced to get it into production. Even if you’re not into poking around on vintage computers, there are lessons to be learned here about what it takes to move from a handful of prototypes to something you can actually sell to the public.

We especially liked the details about the mouSTer enclosure, or lack thereof. Originally [Drygol] says they were going to have the cases injection molded, but despite initial interest from a few companies they talked to, nobody ended up biting because it needed to be done with relatively uncommon low pressure injection. While 3D printing is still an option, the team ended up using clear heatshrink tubing to create a simple conformal protective shell over the electronics. Personally we think it looks great like this, but it sounds like this is only a temporary solution until something a bit more robust can be implemented.

As you might imagine we’ve seen DIY projects that aimed to bring modern input devices to vintage computers like the Atari ST, but the diminutive proportions of the mouSTer and the fact that it’s a turn-key product is sure to appeal to those who want to minimize headaches when working with their classic gear.

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TRS-80 Model 100 Gets 64-Bit CPU And A Very Wide LCD

To say the TRS-80 Model 100 was ahead of its time would be something of an understatement. It had a high-quality mechanical keyboard, phenomenal battery life, plenty of I/O and expansion capabilities, and was actually small and light enough to easily carry around. While its layout might seem to be a bit dated to modern eyes, there’s little debate that it was one of the most successful and influential computers in history.

So it’s little surprise that [belsamber] thought the Model 100 might make an ideal platform for his mobile command line work. With a few modifications, naturally. While technically the nearly 40 year old portable could connect to a Linux computer as a simple serial terminal, its outdated and non-backlit LCD leaves a bit to be desired in 2021. But there’s little sense in upgrading the display if he’d still be saddled with the anemic Intel 80C85 motherboard, so he decided to clean house and replace everything.

Once stripped of the original hardware, the Model 100’s enclosure offered up plenty of room for a Pine A64 LTS single-board computer, four 18650 cells, and a 1920×480 ultra-wide LCD. While not a perfect match for the dimensions of the original panel, the new screen is an exceptionally close fit. The keyboard has been left intact, but rather than adding a QMK-compatible microcontroller to the mix, [belsamber] wired the matrix directly into the GPIO of the A64.

While we know some retro aficionados might shed a tear to see an iconic computer get gutted, [belsamber] mentions that nothing will go to waste; the parts he pulled from this machine will serve as spares for a second Model 100 he has in his collection. Besides, given the immense popularity of these machines, they aren’t exactly rare to begin with.

As an aside, we recently saw this same unique display used in a 3D printed desktop computer with distinctively retro-futuristic styling. We didn’t have miniature 4:1 ratio displays on our list of 2021 hardware predictions, but it seems they’re already making a strong showing.

3D Printed Pi Laptop Honors The Iconic GRiD Compass

If you’re familiar with vintage portable computers, you know about the GRiD Compass. Even if you’re not into computers of yesteryear, there’s a good chance you’ve seen a Compass or two without realizing it. From battling xenomorphs in Aliens to making the trip to orbit aboard the Space Shuttle, the trendsetting clamshell computer seemed to be everywhere in the 1980s. While far too expensive for the average consumer to afford back then, its no-compromise design and sleek looks helped lay the groundwork for today’s ubiquitous laptops.

Getting your hands on a working GRiD Compass in 2021 isn’t a whole lot easier than it was in 1982, so [Mike] decided to do the next best thing and build his own. His GRIZ Sextant certainly isn’t a replica, but the family resemblance is strong enough to get the point across. The Raspberry Pi powered machine has a greatly reduced “trunk” section in the back as you might expect, but the overall layout is very similar. The Commodore 64 inspired color scheme is probably the biggest departure from the source material, but it’s hard to argue with the results.

It’s clear at a glance that a lot of thought was put into the external aesthetics of the Sextant, but a peek under the hood shows the internal details are equally impressive. [Mike] tells us he has a background in product design, and it shows. Rather than approaching this project as a one-off creation, he’s clearly taken great pains to ensure the design is as reproducible as possible.

All of the individual components of the 3D printed frame and enclosure have been carefully designed so they’ll fit within the build volume of the average desktop machine. Electronic components are screwed, not glued, to the internal framework; making future repairs and maintenance much easier. When combined with the ample internal volume available, this modular approach should make adding custom hardware a relatively painless process as well.

So when will you be able to build a GRIZ Sextant of your own? Hopefully, very soon. [Mike] says he still needs to work some kinks out of the power supply and finalize how the speakers will get mounted into the case. Once those last tweaks are locked in, he plans to release all the STL files and a complete Bill of Materials. For those who want to get a sneak peek before they start warming up the extruder, he’s also started documenting the assembly of the Sextant on his YouTube channel. Continue reading “3D Printed Pi Laptop Honors The Iconic GRiD Compass”