Retrocomputing

1624 Articles

CH32V003 Makes For Dirt Cheap RISC-V Computer

May 31, 2024 by 37 Comments

These days, when most folks think of a computer they imagine a machine with multiple CPUs, several gigabytes of RAM, and a few terabytes of non-volatile storage for good measure. With such modern expectations, it can be difficult to see something like a microcontroller as little more than a toy. But if said MCU has a keyboard, is hooked up to a display, and lets you run basic productivity and development software, doesn’t that qualify it as a computer? It certainly would have in the 1980s.

With that in mind, [Olimex] has teased the RVPC, which they’re calling the “world lowest cost Open Source Hardware All-in-one educational RISC-V computer” (say that three times fast). The tiny board features the SOIC-8 variant of the CH32V003 and…well, not a whole lot else. You’ve got a handful of passives, a buzzer, an LED, and the connectors for a PS/2 keyboard, a power supply, and a VGA display. The idea is to offer this as a beginner’s soldering kit in the future, so most most of the components are through-hole.

On the software side, the post references things like the ch32v003fun development stack, and the PicoRVD programmer as examples of open source tools that can get your CH32V computer up and running. There’s even a selection of retro-style games out there that would be playable on the platform. But what [Olimex] really has their eye on is a port of VMON, a RISC-V monitor program.

When paired with the 320×200 VGA text mode that they figure the hardware is capable of, you’ve got yourself the makings of an educational tool that would be great for learning assembly and playing around with bare metal programming.

It might not have the timeless style of the Voja4, but at least you can fit it in a normal sized pocket.

Thanks to [PPJ] for the tip.

Walking Through A Scene From Riven On The Apple II

May 30, 2024 by 8 Comments

Twenty years before the 1997 release of Riven – Cyan’s sequel to the critically acclaimed title Myst – a fruity company in California released the Apple II, a 6502-based microcomputer that would be produced until 1993. With the upcoming remake by Cyan of Riven into a fully 3D experience, [deater] found themselves wondering how much of the original game’s click-and-puzzle game would fit on a 140 kB floppy for the Apple II series of computers. Since Myst was able to be squeezed  onto a mere three floppies and provide a reasonably playable version of the game on the Apple II, surely the same could be done for this sequel?

The Maglev in the Apple II port of Riven. (Credit: [deater])
The Maglev in the Apple II port of Riven. (Credit: [deater])
Just a look at the system requirements for Riven (Win95+, 100 MHz Pentium, 16 MB RAM and 75 MB disk space) and the knowledge that the game came on five CD-ROMs (until the DVD release) should instill some trepidation that a serious demake would be needed. Ultimately [deater] managed to set the system requirements for the port to any Apple II with at least 48 kB of RAM. The same custom game engine as for the Myst port is used, with the original CG stills downsampled and the movies rotoscoped at fairly low framerate.

Although the ‘Disk 39’ in the video is currently the sole floppy, containing part of Dome Island and the Maglev, it is probably a fair assessment of how many 140 kB disks would be needed to port the entire game. Even with the downsampled graphics, [deater] reckons it would take on the order of hundreds of floppies to fit the whole thing.

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The 6809 Lives On In An FPGA

May 28, 2024 by 40 Comments

At one point, the Motorola 6809 seemed like a great CPU. At the time it was a modern 8-bit CPU and was capable of hosting position-independent code and re-entrant code. Sure, it was pricey back in 1981 (about four times the price of a Z80), but it did boast many features. However, the price probably prevented it from being in more computers. There were a handful, including the Radio Shack Color Computer, but for the most part, the cheaper Z80 and the even cheaper 6502 ruled the roost. Thanks to the [turbo9team], however, you can now host one of these CPUs — maybe even a better version — in an FPGA using Verilog.

The CPU may be old-fashioned on the outside, but inside, it is a pipeline architecture with a standard Wishbone bus to incorporate other cores to add peripherals. The GitHub page explains that while the 6809 is technically CISC, it’s so simple that it’s possible to translate to a RISC-like architecture internally. There are also a few enhanced instructions not present on the 6809.

In addition to the source code, you’ll find a thesis and some presentations about the CPU in the repository. While the 6809 might not be the most modern choice, it has the advantage of having plenty of development tools available and is easy enough to learn. Code for the 6800 should run on it, too.

Even using through-hole parts, you can make a 6809 computer fit in a tiny space.You can also break out a breadboard.

One Man’s Trash Is… A Rare $60,000 Historical Computer

May 25, 2024 by 11 Comments

According to Smithsonian Magazine, a salvage company in London was cleaning out a property and found an odd-looking computer device. No one knew what it was, and they couldn’t find anything with a quick online search. The devices in question were two ultra-rare Q1 computers dating from the early 1970s.

While these machines looked formidable, they contained Intel 8008 CPUs but did have built-in screens, keyboards, and printers. The two machines had a few minutes of fame at Kingston University London and are now for sale. They will probably bring about $60,000 each. Not bad for salvage junk.

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How A DOS Format Blunder Revealed Some Priceless Source Code

May 25, 2024 by 14 Comments

As those of us who worked in the consumer software world back when physical media was king can attest, when a master disc has been sent for duplication and distribution there is no turning back from whatever code is in the hands of thousands of users. Usually such worries were confined to bugs or inadvertently sending out pre-release software versions, but [Lance Ewing] is here with the story of how Sierra On-Line once inadvertently released most of the source code for their game engine.

If you have some 720k floppy disk versions of the 1988 game Space Quest II, the first disk in the set appears to have nothing out of the ordinary, but a closer look reveals that the free space on the disk reported by DOS is greater than its used space. Diving in to the disk block contents with a hex editor reveals that many of the unused blocks in fact contain C code, and some further detective work allows the recovery of a not-quite complete set of source files for the company’s AGI, or adventure game interpreter. They had been left behind when the original master disk had been emptied by deleting them, rather than by formatting it afresh.

In commercial terms this would in 1988 have been something of a disaster for Sierra had it been discovered at the time, because it was the cornerstone of their success. As it was we’re told the code sat peacefully undetected until 2016, since when it has proved invaluable to those interested in computer game archaeology. Or did it? We’ll never know if a sharp-eyed competitor snagged it, and kept quiet.

Of course, these days, there are game engines that are open source. Some of them are very modern. Others… not so much.

BASIC Classroom Management

May 25, 2024 by 22 Comments

While we don’t see it used very often these days, BASIC was fairly revolutionary in bringing computers to the masses. It was one of the first high-level languages to catch on and make computers useful for those who didn’t want to (or have time) to program them in something more complex. But that doesn’t mean it wasn’t capable of getting real work done — this classroom management software built in the language illustrates its capabilities.

Written by [Mike Knox], father of [Ethan Knox] aka [norton120], for his classroom in 1987, the programs were meant to automate away many of the drudgeries of classroom work. It includes tools for generating random seating arrangements, tracking attendance, and other direct management tasks as well as tools for the teacher more directly like curving test grades, tracking grades, and other tedious tasks that normally would have been done by hand at that time. With how prevalent BASIC was at the time, this would have been a powerful tool for any educator with a standard desktop computer and a floppy disk drive.

Since most people likely don’t have an 80s-era x86 machine on hand capable of running this code, [Ethan] has also included a docker container to virtualize the environment for anyone who wants to try out his father’s old code. We’ve often revisited some of our own BASIC programming from back in the day, as our own [Tom Nardi] explored a few years ago.

Console Calculator Moves One Step Closer To Original Design

May 24, 2024 by 14 Comments

With smartphone apps and spreadsheets being the main ways people crunch their numbers nowadays, there’s not much call for a desktop calculator. Or any other physical calculator, for that matter. Which is all the more reason to appreciate this  Wang 300-series calculator console’s revival through a new electronic backend.

If you haven’t made the acquaintance of the Wang calculator series, [Bob Alexander]’s previous Wang project is a perfect introduction. Despite looking very much like an overbuilt early-70s desktop calculator, what you see in the video below is just a terminal, one of four that could connect to a shared “Electronics Package” where most of the actual computational work was done. The package was big and is currently hard to come by, at least at a reasonable price, but the consoles, with their Nixie displays and sturdy keypads, are relatively abundant.

[Bob]’s previous venture into reviving his console involved embedding a PIC32-based controller, turning it into the standalone desktop calculator it never was. To keep more with the original design philosophy, [Bob]’s second stab at the problem moves much of the same circuitry from inside the console into a dedicated outboard package, albeit one much smaller than the original. The replacement package extends and enhances the console functionality a bit, adding a real-time clock and a Nixie exercise routine to ward off the dreaded cathode poisoning. [Bob] also recreates the original Wang logarithmic method of multiplication and division, which is a nice touch with its distinctive flashing display.

Seeing the Wang console hooked up to a package through that thick cable and Centronics connector is oddly satisfying. We’d love to see [Bob] take this to the logical extent and support multiple consoles, but that might be pushing things a bit.

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