Bringing A Chain Printer Back To Life: The Power Supply

[Usagi Electric] has his Centurion minicomputer (and a few others) running like a top.  One feature that’s missing, though, is the ability to produce a hard copy. Now, a serious machine like the Centurion demands a serious printer. The answer to that is an ODEC-manufactured printer dressed in proper Centurion blue. This is no ordinary desktop printer, though. It’s a roughly 175lb (80 Kg) beast capable of printing 100 lines per minute. Each line is 132 characters wide, printed on the tractor-feed green bar paper we all associate with old computer systems.

This sort of printer was commonly known as a chain printer, as the letters are on a chain that rides over a series of 66 hammers. Logic on this printer is 74 series logic chips – no custom silicon or LSI (Large Scale Integration) parts on this 47-year-old monster.

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The Sol-1: A 16-bit Computer In 74HC Logic With C Compiler And Unix-like OS

Sol-1 system pictured from the front. {Credit: Paulo Constantino)
Sol-1 system pictured from the front. {Credit: Paulo Constantino)

While the concept of a computer system implemented in discrete logic ICs is by itself not among the most original ideas, the way some machines are executed certainly makes them stick out. This is the case with [Paulo Constantino]’s Sol-1, which not only looks extremely professional, but also comes with a lot of amenities that allow for system development, including a C compiler and assembler, a Unix-like OS (in development), DMA, and a whole host of interfaces to interact with the system and peripherals (serial, parallel, IDE, etc.). Not to mention a SystemVerilog model and an emulator, all of which can be found on [Paulo]’s GitHub.

More photos and videos can be found on [Paulo]’s YouTube channel, as well as the Sol-1 website, which shows off the intricate wire wrap work on the back of each PCB. In terms of the ISA, there are 5 general purpose registers (one scratch) which can also be used as two 8-bit registers each. Most operations are supported, except for floating point. For future improvements and additions, Sol-1’s OS will get more features added, and the first major software to be ported to the Sol-1 should be Colossal Cave Adventure and similar text-based adventure (dungeon) games.

Cowgol Development Environment Comes To Z80 And CP/M

Cowgol on Z80 running CP/M ties together everything needed to provide a Cowgol development environment (including C and assembler) on a Z80 running the CP/M operating system, making it easier to get up and running with a language aimed to be small, bootstrapped, and modern.

Cowgol is an experimental modern language for (very) small systems.

The Zilog Z80 was an 8-bit microprocessor common in embedded systems of the 1970s and 1980s, and CP/M was a contemporary mass-market operating system. As for Cowgol? It’s an Ada-inspired compiler toolchain and programming language aimed at very small systems, such as the Z80.

What’s different about Cowgol is that it is intended to be self-hosted on these small systems; Cowgol is written in itself, and is able to compile itself. Once one has compiled the compiler for a particular target architecture (for example, the Z80) one could then use that compiler on the target system to compile and run programs for itself.

Thankfully, there’s no need to start from scratch. The Cowgol on Z80 running CP/M repository (see the first link of this post) contains the pre-compiled binaries and guidance on using them.

Cowgol is still under development, but it works. It is a modern language well-suited to (very) small systems, and thanks to this project, getting it up and running on a Z80 running CP/M is about as easy as such things can get.

Thanks to [feinfinger] for the tip!

Is Microsoft BASIC Hidden In This Educational Child’s Toy?

The VTech PreComputer 1000 is a rather ancient toy computer that was available in the distant misty past of 1988. It featured a keyboard and a variety of simple learning games, but does it also feature Microsoft BASIC? [Robin] of 8-Bit Show and Tell dove in to find out.

Officially, the PreComputer was programmable in a form of BASIC, referred to by VTech as PRE-BASIC V1.0. Given that the system has a Z80 CPU and there’s little information in the manual about this programming language, [Robin] was suspicious as to whether it was based on Microsoft BASIC-80. Thus, an examination was in order to figure out just how this BASIC implementation worked, and whether it shared anything with Microsoft’s own effort.

We won’t spoil the conclusions, but there are some strong commonalities between VTech’s BASIC and Microsoft’s version from this era. The variable names in particular are a strong hint as to what’s going on under the hood. The video is worth a watch for anyone that’s a fan of early microcomputer history, BASIC, or just the weird computer-like devices of yesteryear. We also love the idea that the PreComputer 1000 was actually quite a capable machine hiding behind a single-line LCD display.

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Reliving The Authentic 90s Linux Experience

Installing Linux on a modern PC has never been easier. There are tons of tools available that will nearly-automatically download your Linux distribution of choice, image a USB drive, and make it bootable so you can finally ditch your bloated, privacy-violating operating system and get the free performance boost that comes along with it. This wasn’t always the case, though. In the 90s you had to take a trip to a store (or library) and buy (or borrow) a boxed copy of some variety of Linux on floppy disk or CDs, and then install it on your own, often without the help of the Internet. [Action Retro] demonstrates this process for us so we don’t have to relive the pain ourselves.

Complete with a 90s-era Pentium machine enclosed in a beige case, this is really the full 90s experience. He’s found a boxed version of Red Hat version 5.2 with everything needed to get it up and running and, after a brief issue with the installer crashing because it couldn’t figure out the ZIP disk drive, had another era-appropriate experience by erasing the existing Windows 98 installation. This was before automatic partitioning tools were widely available, so it was a real risk for beginner Linux enthusiasts if they were trying to dual boot.

With the installation complete, the X window system still needed to be set up, as well as making sure the settings for the old CRT monitor were correct. With everything finalized, the system can really be explored. It includes out-of-the-box some software plenty of us would recognize today such as GIMP and some other software we might not, like Netscape Communicator. It’s a real time machine experience to get this operating system running on period-appropriate hardware, and a lot of features of modern Linux systems can still be seen especially if your modern distribution of choice still requires a lot of manual configuration during installation. Old operating systems aside, this machine might be capable of running a modern Linux distribution as well, provided it has something slightly newer than a 486.

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Vintage Computer Festival Southern California

The Vintage Computer Festival is coming to sunny Southern California in February 2024. That’s right, bring your Commodores, your Tandys,  your PDP-11s, and Altairs. The world of retrocomputing will be open to vendors, visitors, and exhibitors at The Hotel Fera Events Center in Orange, California on February 17th and 18th, 2024.

If you’re thinking there already is a VCF out west, you’d be right. VCF West was held in August at the Computer History Museum. The CHM is in Mountain View, California. That puts it nearly at the epicenter of the microcomputer revolution of the ’70s and ’80s.

Southern California still had plenty of computer enthusiasts though. For the non-geographically inclined amongst us, SoCal is nearly 6 hours from Mountain View by car.  We’re sure we’ll see many familiar faces at SoCal, along with plenty of new ones.

The Vintage Computer Federation holds several events across the country each year. You might have heard some music from VCF Midwest 2023 back in September. Hackaday was also out in force at VCF East this year, where our own [Bil Herd] moderated a panel of vintage computer YouTubers including [Usagi Electric], [Adrian’s Digital Basement], and [FranLab].

RP2040 Emulator Brings The Voice Of The 80s Back To Life

You may not have heard, but there’s a chip shortage out there. And it’s not just the fancy new chips that are in short supply; the chips that were fancy and new back when you could still buy them from Radio Shack are getting hard to come by, too. For different reasons, of course, but it does pose a problem that requires a little hacking to fix.

The chip in question here is the General Instrument SP0256, a 1980s-era speech synthesizer chip that [Andrew Menadue] relies on. The LSI chip stored 59 unique allophones, or basic sounds the vocal tract is capable of, and synthesized speech by rapidly concatenating these sounds. The chip and its descendants made regular appearances in computers and games throughout the 80s, so chances are good you’ve heard it. If not, think WarGames (yes, we know that wasn’t actually a computerized voice) or [Stephen Hawking] and you’ll be pretty close.

[Andrew]’s need for such a chip stems from his attempts to give voice to his collection of Psion Organisers, another 80s relic that was one of the first pocket computers. Some time ago he built a speech board for the Psion based on the SP0256-AL2, but had to resort to building an emulator for the chip since none were to be had. The emulator uses an RP2040 and lives on a PCB that has the same footprint as the original chip, so it can just plug right in. He dug up WAV files of the allophones and translated those to sequences of bytes, allowing the RP2040 to output the correct sounds as they’re called for. Speaker problems notwithstanding, it sounds pretty good in the video below.

We’ve featured a fair number of SP0256 projects before, on everything from Amstrad to Z80. We’ve also shown off a few of [Andrew]’s builds before, including this exploration of the voltage tolerance of the RP2040.

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