Re-reclaimed From Nature: Resurrecting A DT80 Terminal

July 30, 2022 by Sven Gregori 8 Comments

When Datamedia announced their new DT80 terminal as a VT100 killer back in 1979, they were so confident of its reliability, they threw in a full one-year warranty. Now, decades later, that confidence is once more put to the touch after [RingingResonance] fished one such terminal out of a creek by an old illegal dumping site. Not knowing what to expect from the muck-ridden artifact, his journey of slowly breathing life back into the device began.

Considering the layers of mud and roots already growing all over the main board, one can only assume how long the terminal has actually been in there. But cleaning it from all that was only the beginning: some components were missing, others turned out to be broken, including some of the ROMs, which [RingingResonance] speculates may have been caused by lightning which determined the DT80’s fate in the first place.

That’s when the adventure really started though, digging deep into the terminal’s inner life, eventually writing a debugger and own firmware for it. That code, along with all other research, notes, and links to plenty more pictures can be found in the GitHub repository, and is definitely worth checking out if you’re into the technologies of yesteryear.

Despite the DT80’s claimed superiority, the VT100 prevailed and is the terminal that history remembers — and emulates, whether as tiny wearable or a full look-alike. But this fall into oblivion was also part of [RingingResonance]’s motivation to keep going forward restoring the DT80. Someone had to. So if you happen to have anything to contribute to his endeavours or share with him, we’re sure he will appreciate you reaching out to him.

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Hackaday Prize 2022: Modern Plug-in Gives TRS-80 Its Voice Back

July 29, 2022 by Robin Kearey 9 Comments

Like artificial intelligence, speech synthesis was one of those applications that promised to revolutionize computing in the 1980s, only to fizzle out after people realized that a robotic voice reading out predefined sentences was not actually that useful. Nevertheless, computer manufacturers didn’t want to miss out on the hype and speech synthesizers became a relatively common add-on for a typical home computer.

Those add-ons were usually built around a custom voice-synthesis chip. If that chip fails, you’re out of luck: many were made in limited quantities by small companies and are impossible to find today. So if you’ve got a Tandy TRS-80 Voice Synthesizer with a dodgy SC-01-A chip, you’ll definitely want to check out [Michael Wessel]’s Talker/80 project. It’s a plug-in module for the TRS-80 that’s software compatible with the original Voice Synthesizer, but built from modern components. Synthesis is still performed by a custom IC, but now it’s using the more common Epson S1V30120 text-to-speech chip.

The Talker/80 also has an ATmega644, which connects to the TRS-80’s expansion port on one side and to the Epson chip on the other. It can either emulate the original SC-01-A, in which case it expects text to be split into separate phonemes, or it can be set to an “advanced” mode in which it can directly process normal English text. In either case the voice sounds quite different from what original, although the new voice is arguably a little clearer.

We’ve seen modern speech synthesizers made for several classic computers: you can hook up the same Epson chip to an Amstrad CPC, or an ESP8266 to a VIC-20. If you’ve got an actual working SC-01-A but no vintage computer to use it with, you can also control it with an Arduino.

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PERSEUS-9, The Dual-6502 Portable Machine That Should Have Been

July 29, 2022 by Dan Maloney 53 Comments

A question: does anyone who was around in the early days of the 8-bit computer revolution remember a dual-CPU 6502 portable machine like this one? Or just a dual-CPU machine? Or even just a reasonably portable computer? We don’t, but that begs a further question: if [Mitsuru Yamada] can build such a machine today with parts that were available in the era, why weren’t these a thing back then?

We’re not sure we have an answer to that question, but it just may be that nobody thought of it. Or, if they did, the idea of putting two expensive CPUs into a single machine was perhaps too exorbitant to take seriously. Regardless, the homemade mobile is another in a growing line of beautifully crafted machines in the PERSEUS line, all of which have a wonderfully similar look and feel.

For the PERSEUS-9, [Yamada-san] chose a weatherproof aluminum enclosure with just the right form-factor for a mobile computer, as well as a sturdy industrial look. Under the hood, there are two gorgeous wire-wrap boards, one of which is home to the 48-key keyboard and the 40×7 alphanumeric LED matrix display, while the other is a densely packed work of art holding the two 6502s and a host of other DIPs.

The machine is a combination of his PERSEUS-8 computer, his 6802 serial terminal, and the CI-2 floating point interpreter he built for the PERSEUS-8. A brief video of the assembly of this delightful machine is below. One of the many things about these builds that impress us is the precision with which the case is machined, apparently all by hand. How he managed to drill out all those holes for the keyboard without having one even slightly out of alignment without the aid of CNC is beyond us.

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New OS For Commodore 64 Adds Modern Features

July 28, 2022 by Bryan Cockfield 45 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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Your Own Engineering Workstation, With Mame

July 28, 2022 by Al Williams 19 Comments

There are some things that leave indelible impressions in your memory. One of those things, for me, was a technical presentation in 1980 I attended — by calling in a lot of favors — a presentation by HP at what is now the Stennis Space Center. I was a student and it took a few phone calls to wrangle an invite but I wound up in a state-of-the-art conference room with a bunch of NASA engineers watching HP tell us about all their latest and greatest. Not that I could afford any of it, mind you. What really caught my imagination that day was the HP9845C, a color graphics computer with a roughly $40,000 price tag. That was twice the average US salary for 1980. Now, of course, you have a much better computer — or, rather, you probably have several much better computers including your phone. But if you want to relive those days, you can actually recreate the HP9845C’s 1980-vintage graphics glory using, of all things, a game emulator.

The Machine

The HP9845C with a Colorful Soft Key Display

Keep in mind that the IBM PC was nearly two years away at this point and, even then, wouldn’t hold a candle to the HP9845C. Like many machines of its era, it ran BASIC natively — in fact, it used special microcode to run BASIC programs relatively quickly on its 16-bit 5.7 MHz CPU. The 560 x 455 pixel graphics system had its own CPU and you could max it out with a decadent 1.5 MB of RAM. (But not, alas, for $40,000 which got you — I think –128K or so.)

The widespread use of the computer mouse was still in the future, so the HP had that wonderful light pen. Mass storage was also no problem — there was a 217 kB tape drive and while earlier models had a second drive and a thermal printer optional, these were included in the color “C” model. Like HP calculators, you could slot in different ROMs for different purposes. There were other options such as a digitizer and even floppy discs.

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Hackaday Prize 2022: Repairing A Vintage Laptop With Modern Components

July 27, 2022 by Robin Kearey 23 Comments

Laptop computers may be ubiquitous today, but there was a time when they were the exclusive preserve of rich businesspeople. Back in the early ’90s, the significant added cost of portability was something that few were willing to pay. As a result, not many laptops from those days survive; for those that do, keeping them running can be quite a challenge due to their compact construction and use of non-standard components.

[Adalbert] ran into these problems when he got his hands on a Toshiba T3200SXC from 1991. As the first laptop ever to feature a color TFT display, it’s very much worth preserving as an historical artifact. Sadly, the original display was no longer working: it only displayed a very faint image and went completely blank soon after. Leaky capacitors then destroyed the power supply board, leaving the laptop completely dead. [Adalbert] then began to ponder his options, which ranged from trying to repair the original components to ripping everything out and turning this into a modern-computer-in-an-old-case project.

In the end he went for an option in between, which we as preservationists can only applaud: he replaced the display with a modern one of the correct size and resolution and built a new custom power supply, keeping the rest of the computer intact as far as possible. [Adalbert] describes the overall process in the video embedded below and goes into lots of detail on his hackaday.io page.

Connecting a modern LCD screen was not as difficult as it might seem: where the old display had an RGB TTL interface with three bits per color, the new one had a very similar system with six bits per color. [Adalbert] made an adapter PCB that simply connected the three bits from the laptop to the highest three bits on the screen. A set of 3D-printed brackets ensured a secure fit of the new screen in the classic case.

For the power supply [Adalbert] took a similar approach. He designed a PCB with several DC/DC converters that fit easily inside the computer’s case, leaving enough space to add a battery. This made the old Toshiba more portable than it ever was — believe it or not, the original T3200SXC could only be used with a mains connection.

Once the laptop was restored to working order, [Adalbert] added a few finishing touches: a sound card and speakers made it suitable as a gaming platform, and a network card gave it rudimentary online capabilities. The end result is a T3200SXC that looks and feels exactly the way it did when it was new, but with a few added features. That’s a really satisfying result: many classic laptop projects add modern computing hardware, or even completely replace the original contents. You might also want to check out [Adalbert]’s unusual 3D printer based PCB manufacturing technique that he used for the new power supply.

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Up Close And Personal With An 8x Floppy Controller

July 25, 2022 by Tom Nardi 44 Comments

In need of a floppy controller for a 286 he was working on, [Gadget Reboot] took to GitHub to see what was available in the open hardware space. There he found an ISA board capable of controlling up to eight drives from [Sergey Kiselev] called the Monster Floppy Disk Controller (FDC) — arguably overkill for the task, but too impressive to pass up. Luckily for us, he decided to document the build process in a video that covers everything from ordering the boards to configuring the BIOS.

The video starts with a high-level overview of the schematic, which as you might have guessed, essentially puts two identical floppy controllers on the same board. You can tell this design was put together during the current chip shortage, as [Sergey] was careful to include some wiggle room if certain parts became unavailable and had to be swapped out for the alternatives listed in the BOM. It’s a decision that already paid off for [Gadget Reboot], as in some cases he had to go with the second-choice ICs.

[Gadget Reboot] was in for something of a surprise when he submitted the board for fabrication, as selecting the option for gold contacts on the edge connector made the production cost jump from $5 to nearly $300. He details how he was able to bring that cost back down a bit, but it still ended up being more than 10 times as expensive as the base price.

The second half of the video is dedicated to configuring the Monster FDC, which will certainly be a helpful resource for anyone looking to put this board to work in their own system. [Gadget Reboot] demonstrates using the board with “only” four floppy drives, and everything looks to work quite well.

Of course if your needs aren’t quite so grandiose, we’ve seen some more expedient floppy controllers which might be closer to what you’re looking for.

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