Classroom Surplus Becomes Linux Powerhouse

July 27, 2021 by Jenny List 30 Comments

The SMART Response XE is a handheld computer that was originally sold for use in the classroom as a terminal for pupils taking tests. It’s now cheap enough on the surplus market to have become a target for experimenters, and we’ve seen them with a variety of cool hacks. We particularly like what [chmod775] has done with it, putting a VT100 terminal emulator on the device and hiding a NanoPi Neo Air single board computer in the battery bay. Powered from a USB battery bank, it gives a fully-featured Linux terminal in the palm of the hand. We see it running an Ubuntu LTS version, and it’s clear that it’s a functional and usable device.

This raises a more abstract question though: We’d guess comparatively few of us write software through an old-style dumb terminal, instead we’re more likely to get our terminal experience at a much more accomplished command line with all the conveniences of a modern desktop surrounding it. How many of us could comfortably return to the limited confines of a VT100 emulator on an odd-sized LCD display? We’d be interested to hear [chmod755]’s experiences using it, because if it retains usability it’s a device we wouldn’t mind having ourselves.

Hungry for more SMART Response XE hacks? Take a look at the BASIC computer, or the spectrum analyser.

Installing Linux Like It’s 1989

June 30, 2021 by Bryan Cockfield 34 Comments

A common example of the sheer amount of computing power available to almost anyone today is comparing a smartphone to the Apollo guidance computer. This classic computer was the first to use integrated circuits so it’s fairly obvious that most modern technology would be orders of magnitude more powerful, but we don’t need to go back to the 1960s to see this disparity. Simply going back to 1989 and getting a Compaq laptop from that era running again, while using a Raspberry Pi Zero to help it along, illustrates this point well enough.

[befinitiv] was able to get a Raspberry Pi installed inside of the original computer case, and didn’t simply connect the original keyboard and display and then call it a completed build. The original 286 processor is connected to the Pi with a serial link, so both devices can communicate with each other. Booting up the computer into DOS and running a small piece of software allows the computer into a Linux terminal emulator hosted on the Raspberry Pi. The terminal can be exited and the computer will return back to its original DOS setup. This also helps to bypass the floppy disk drive for transferring files to the 286 as well, since files can be retrieved wirelessly on the Pi and then sent to the 286.

This is quite an interesting mashup of new and old technology, and with the Pi being around two orders of magnitude more powerful than the 286 and wedged into vacant space inside the original case, [befinitiv] points out that this amalgamation of computers is “borderline useful”. It’s certainly an upgrade for the Compaq, and for others attempting to get ancient hardware on the internet, don’t forget that you can always use hardware like this to access Hackaday’s retro site.

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3D Printed Terminal Takes Computing Back In Time

May 13, 2021 by Tom Nardi 14 Comments

It’s hard to look at today as anything but the golden age of computing. Even entry level machines have quad-core processors and a terabyte or more of storage space, to say nothing of the incredible amount of tech packed into the modern smartphone. But even so, there’s something to be said for the elegant simplicity of early desktop computers.

Looking to recreate the feeling of those bygone days, [Pigeonaut] created the Callisto II. Its entirely 3D printed case snaps together without glue or screws, making it easy to assemble, and the parts have been sized so they’ll be printable even on smaller machines like the Prusa Mini. Inside you’ll find a 1024×768 Pimoroni HDMI 8″ IPS LCD, 60% mechanical keyboard, four-port USB 3 hub, Raspberry Pi 4, and a 22 watt USB power supply to run it all.

The internal components can be easily accessed with the hatch on the rear of the case, and there’s plenty of room inside to add new hardware should you want to toss in a hard drive or even swap out the Pi for a different single-board computer.

To really drive home the faux-retro concept of the Callisto II, [Pigeonaut] has created a website for the fictional computer company behind the machine, replete with all the trappings you’d expect from the early web. There’s even a web-based “operating system” you can use to show off your freshly printed Callisto II.

Incidentally the II suffix isn’t just part of the meme, there really was a Callisto before this one. We covered the earlier machine back in 2019, and while we’re a bit sad to see that the functional 3.5 inch floppy drive has been deleted, we can’t deny the overall aesthetics have been greatly improved in the latest version.

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Minimal UART Computer

March 17, 2021 by Chris Lott 25 Comments

[Carsten] spent over a year developing a small CPU system, implementing his own minimalist instruction set entirely in TTL logic. The system uses a serial terminal interface for all I/O, hence the term UART in the title. [Carsten] began building this computer on multiple breadboards, which quickly got out of hand.

He moved the design over to a PCB, but he was still restless. This latest revision replaces EEPROM with cheaper and easier to use CMOS Flash chips, and the OS gains a small file system manager. As he says in the video, his enemy is feature creep.

In addition to designing this CPU project, [Carsten] built an assembler and wrote a substantial operating system and various demo programs and games. He not only learned KiCAD to make this board, but also taught himself to use an auto-router. The KiCAD design, Gerbers, and BOM are all provided in his repository above. ROM images and source code are provided, as well as a Windows cross-assembler. But wait – there’s more. He also wrote a cycle exact emulator of the CPU, which, as he rightfully brags, comes in at under 250 lines of C++ code. This whole project is an amazing undertaking and represents a lot of good work. We hope he will eventually release the assembler project as well, in case others want to take on the challenge of building it to run under Linux or MacOS. Despite this, the documentation of the Minimal UART Computer is excellent.

[Carsten] claims the project has finally passed the finish line of his design requirements, but we wonder, will he really stop here? Do check out his YouTube channel for further informative videos. And thanks to [Bruce] for sending in the tip.

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Print-in-Place Connectors Aim To Make Wiring Easier

February 15, 2021 by Dan Maloney 115 Comments

One thing some of us here in the United States have always been jealous of is the WAGO connectors that seem so common in electrical wiring everywhere else in the world. We often wonder why the electrical trades here haven’t adopted them more widely — after all, they’re faster to use than traditional wire nuts, and time is money on the job site.

Wago 221 compact lever connector via the Wago YouTube channel

This print-in-place electrical connector is inspired by the WAGO connectors, specifically their Lever Nut series. We’ll be clear right up front that [Tomáš “Harvie” Mudruňka’s] connector is more of an homage to the commercially available units, and should not be used for critical applications. Plus, as a 3D-printed part, it would be hard to compete with something optimized to be manufactured in the millions. But the idea is pretty slick. The print-in-place part has a vaguely heart-shaped cage with a lever arm trapped inside it.

After printing and freeing the lever arm, a small piece of 1.3-mm (16 AWG) solid copper wire is inserted into a groove. The wire acts as a busbar against which the lever arm squeezes conductors. The lever cams into a groove on the opposite wall of the cage, making a strong physical and electrical connection. The video below shows the connectors being built and tested.

We love the combination of print-in-place, compliant mechanisms, and composite construction on display here. It reminds us a bit of these printable SMD tape tamers, or this print-in-place engine benchmark.

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Retro Terminals Bring Some Style To Your Desktop

January 11, 2021 by Tom Nardi 23 Comments

It wasn’t so long ago that a desktop computer was just a beige box with another, heavier, beige box sitting next to it or maybe perched on top. They’re a bit more visually exciting these days, with even mass produced PCs now shipping with RGB lighting and clear side panels. But even so, few could really look at a modern desktop computer and call it objectively beautiful.

But [Oriol Ferrer Mesià] wonders if we couldn’t improve on things a bit. Over the last few months, he’s been experimenting with small 3D printed enclosures that reimagine the traditional desktop computer aesthetic. With their distinctively retro-futuristic style, they look like the kind of gadgets science magazines in the 1960s thought would be dotting kitchens, living rooms, and space stations by the year 2000. But unlike those fanciful creations, each one of these beauties is a fully functional computer.

A few of the designs are relatively conservative, and not entirely unlike some of the old “dumb terminals” of the 1970s. With a Raspberry Pi 4 and a tablet-sized screen, these diminutive terminals would be perfectly usable for light desktop work or some retro gaming.

But we particularly like the ultra-widescreen design that [Oriol] has come up with. With a fairly unusual 4:1 aspect ratio LCD, the printed enclosure for this one was so large that it had to be done in two pieces on his Ender 3. To keep the 8″ 1920 x 480 panel well fed, this design uses a Jetson Nano 2GB which has considerably more graphical punch than other Linux SBCs of similar size and price.

As part of the recent cyberdeck craze, we’ve seen plenty of people recreating the look and feel of vintage portable computers with 3D printed cases and modern components. Desktop creations have been far less common, but with gorgeous designs like these to serve as inspiration, that may change.

A Portable Serial Terminal That Should Be From The 1970s

December 8, 2020 by Jenny List 38 Comments

The humble standalone serial terminal might be long gone from the collective computing experience, but in the ghostly form of a software virtual terminal and a serial converter it remains the most basic fall-back and essential tool of the computer hardware hacker. [Mitsuru Yamada] has created the product that should have been made in the serial terminal’s heyday, a standalone handheld terminal using a 6809 microprocessor and vintage HP dot matrix LEDs. In a die-cast box with full push-button keyboard it’s entirely ready to roll up to a DB-25 wall socket and log into the PDP/11 in the basement.

Using today’s parts we might achieve the same feat with a single-chip microcontroller and a small LCD or OLED panel, but with an older microcomputer there is more system-building required. The 6809 is a wise choice from the 1970s arsenal because it has some on-board RAM, thus there’s no need for a RAM chip. Thus the whole thing is achieved with only a 2716 EPROM for the software, a 6850 UART with MAX232 driver for the serial port, and a few 74 chips for glue logic, chip selects, and I/O ports to handle keyboard and display. There’s no battery in the case, but no doubt that could be easily accommodated. Also there’s not much information on the keyboard itself, but in the video below we catch a glimpse of its wiring as the box is opened.

The value in a terminal using vintage parts lies not only in because you can, but also in something that can’t easily be had with a modern microcontroller. These parts come from a time when a computer system had to be assembled as a series of peripherals round the microprocessor because it had few onboard, leading to a far more in-depth understanding of a computer system. It’s not that a 6809 is a sensible choice in 2020, more that it’s an interesting one.

By comparison, here’s a terminal using technology from today.

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