commodore

124 Articles

Software Defined Retro ROM Makes 8-bit Easy

July 5, 2025 by 28 Comments

Like the rest of us, 8-bit hardware is not getting any newer, and failed ROMs are just a fact of life. Of course you can’t call up Commadore corporation for replacement parts anymore, so something is needed. [Peirs Rocks] wasn’t satisfied with the existing options, so he came up with the Software Defined Retro ROM to serve as a drop-in replacement for 2364, 2332, and 2316 ROM chips.

Physically, the Software Defined Retro ROM is a PCB that matches the footprint of the original ROM chip, and holds an STM32F4 family microcontroller with a number of extra pins facing upwards. Some of those pins are for programming, so you can flash the board in-situ without removing it from the system using a Pi Pico. The others pins are jumpers for image selection or chip configuration. Depending which STM32 you use, you can have upto 16 ROM images on the board, at whatever chip select behaviour you require. The ROM’s chip select lines could be configured at the factory to answer to HIGH or LOW, and this board can handle either with a jumper swap.

The documentation on the GitHub is very well done, for which we applaud [Piers]. Instructions and demos are also available in the video embedded below. We could certainly see this hack becoming popular in the retrocomputer community, especially as everything ages and memories continue to, uh, y’know. What were we talking about, again?

Oh, right, ROMs. You might think an mask ROM would last a very long time, but it’s been a very long time since some of these were made. Best to dump them while you still can. If the chip is really far gone electrically, you might try decoding a photograph of the die.

 

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Let’s Buy Commodore! Well, Somebody Is.

June 7, 2025 by 62 Comments

When a man wearing an Atari T-shirt tells you he’s buying Commodore it sounds like the plot for an improbable 1980s movie in which Nolan Bushnell and Jack Tramiel do battle before a neon synthwave sunset to a pulsating chiptune soundtrack. But here on the screen there’s that guy doing just that, It’s [Retro Recipes], and in the video below he’s assembling a licensing deal for the Commodore brand portfolio from the distant descendant of the Commodore of old.

It’s a fascinating story and we commend him for tracing a path through the mess that unfolded for Commodore in the 1990s. We tried the same research path with a friend a few years ago and ended up with an anonymous Dutch paper company that wouldn’t answer our calls, so we’re impressed. In conjunction with several other players in the Commodore retrocomputing world he’s trying to assemble a favourable percentage deal for manufacturers of new parts, computers, and other goodies, and we’re pleased to see that it’s for the smaller player as much as for the industry giant.

When looking at a story like this though, it’s important not to let your view become clouded by those rose tinted glasses. While it’s great that we’re likely to see a bunch of new Commodore-branded Commodore 64s and parts, there are many pitfalls in taking it beyond that. We’ve seen the Commodore logo on too many regrettable licensed products in the past, and we fear it might be too tempting for it to end up on yet another disappointing all-in-one video game or just another budget PC. If something new comes out under the Commodore brand we’d like it to be really special, exploiting new ground in the way the Amiga did back in the day. We can hope, because the alternative has dragged other famous brands through the mud in recent years.

If you want an insight into the roots of the original Commodore’s demise, have a read of our Hackaday colleague [Bil Herd]’s autobiography.

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A New Mechanical Keyboard For An Old Computer

April 10, 2025 by 9 Comments

As computers age, a dedicated few work towards keeping some of the more interesting ones running. This is often a losing battle of sorts, as the relentless march of time comes for us all, human and machine alike. So as fewer and fewer of these machines remain new methods are needed to keep them running as best they can. [CallousCoder] demonstrates a way of building up a new keyboard for a Commodore 64 which both preserves the original look and feel of the retro computer but also adds some modern touches.

One of the main design differences between many computers of the 80s and modern computers is that the keyboard was often built in to the case of the computer itself. For this project, that means a custom 3D printed plate that can attach to the points where the original keyboard would have been mounted inside the case of the Commodore. [CallousCoder] is using a print from [Wolfgang] to get this done, and with the plate printed and a PCB for the keys it was time to start soldering. The keyboard uses modern switches and assembles like most modern keyboards do, with the exception of the unique layout for some of the C64 keys including a latching shift key, is fairly recognizable for anyone who has put together a mechanical keyboard before.

[CallousCoder] is using the original keycaps from a Commodore 64, so there is an additional step of adding a small adapter between the new switches and the old keycaps. But with that done and some amount of configuring, he has a modern keyboard that looks like the original. If you’re more a fan of the original hardware, though, you can always take an original C64 keyboard and convert it to USB to use it on your modern machines instead.

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Copying Commodore Data Tapes, 40 Years Late

February 28, 2025 by 41 Comments

Unless you handle the backups for a large corporation, bank, or government entity, you likely haven’t stored much data to tape recently. But magnetic storage used to be fairly mainstream back in the 1980s for all kinds of computer programs. Plenty of computers used standard cassette tapes for this too but you couldn’t just copy them with standard audio equipment. You’d need something like this 1560 datasette from [Jan].

The core problem with using Hi-Fi equipment to copy tapes storing data instead of audio is that data tapes need to be much more precise in order to avoid losses that might not be noticeable in an audio recording. In the 80s computer companies like Commodore built tape drives specifically for their computers, so [Jan]’s project uses two of these 1530 drives to build this “1560” datasette. (No working 1530 hardware was harmed in this build.) An inverter circuit in one tape deck is used to provide the signal to write the data to the other tape, reliably copying data from these data tapes in a way Hi-Fi never could.

[Jan] does lament not having something like this back in the 80s when the Commodore was in its heyday, but there’s still a dedicated retrocomputing scene for these machines that will get plenty of use out of projects like this. If you need to go the other direction in time, there are also interfaces that allow data tapes from old Commodores to be read by modern computers with USB.

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Satellite Internet On 80s Hardware

February 14, 2025 by 2 Comments

Portability has been a goal of a sizable section of the computing world for many decades now. While the obvious products of this are laptops, there are a number of “luggable” PCs that pack more power while ostensibly maintaining their portability. Going back in time past things like the LAN party era of the 90s and 00s takes us to the early era of luggables, with the Commodore SX-64 being one such machine of this era. Its portability is on display in this video where [saveitforparts] is using it to access the Internet over satellite.

The project uses a Glocom Inmarsat modem and antenna to access the internet through a geostationary satellite, but since this computer is about four decades old now this takes a little bit more effort than a modern computer. A Teensy microcontroller is used to emulate a modem so that the Ethernet connection from the satellite modem can be understood by the Commodore. There was a significant amount of setup and troubleshooting required as well, especially regarding IP addresses and networking but eventually [saveitforparts] got the system up and running well enough to chat on a BBS and browse Wikipedia.

One thing he found that might make a system like this relevant for a modern user is that the text-only mode of the Commodore significantly limited data use. For a normal Internet connection this might be a problem, but on a geostationary satellite network where the data is orders of magnitude more expensive, this can be surprisingly helpful. We might not recommend an SX-64 system specifically, but one inspired by similar computers like this text-only cyberdeck might do the trick with the right networking connections.

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8-Bit Computers Crunch Advanced Scientific Computations

December 1, 2024 by 37 Comments

Although largely relegated to retrocomputing enthusiasts and embedded systems or microcontrollers now, there was a time when there were no other computers available other than those with 8-bit processors. The late 70s and early 80s would have seen computers with processors like the Motorola 6800 or Intel 8080 as the top-of-the-line equipment and, while underpowered by modern standards, these machines can do quite a bit of useful work even today. Mathematician [Jean Michel Sellier] wanted to demonstrate this so he set up a Commodore 64 to study some concepts like simulating a quantum computer.

The computer programs he’s written to do this work are in BASIC, a common high-level language of the era designed for ease of use. To simulate the quantum computer he sets up a matrix-vector multiplication but simplifies it using conditional logic. Everything is shown using the LIST command so those with access to older hardware like this can follow along. From there this quantum computer even goes as far as demonstrating a quantum full adder.

There are a number of other videos on other topics available as well. For example, there’s an AmigaBasic program that simulates quantum wave packets and a QBasic program that helps visualize the statistical likelihood of finding an electron at various locations around a hydrogen nucleus. While not likely to displace any supercomputing platforms anytime soon, it’s a good look at how you don’t need a lot of computing power in all situations. And, if you need a refresher on some of these concepts, there’s an overview on how modern quantum computers work here.

Using AI To Help With Assembly

November 7, 2024 by 30 Comments

Although generative AI and large language models have been pushed as direct replacements for certain kinds of workers, plenty of businesses actually doing this have found that using this new technology can cause more problems than it solves when it is given free reign over tasks. While this might not be true indefinitely, the real use case for these tools right now is as a kind of assistant to certain kinds of work. For this they can be incredibly powerful as [Ricardo] demonstrates here, using Amazon Q to help with game development on the Commodore 64.

The first step here was to generate code that would show a sprite moving across the screen. The AI first generated code in all caps, as was the style at the time of the C64, but in [Ricardo]’s development environment this caused some major problems, so the code was converted to lowercase. A more impressive conversion was done in the next steps, as the program needed to take advantage of the optimizations found in the Assembly language. With the code converted to 6502 Assembly that can run on the virtual Commodore, [Ricardo] was eventually able to show four sprites moving across the screen after several iterations with the AI, as well as change the style of the sprites to arbitrary designs.

Although the post is a bit over-optimistic on Amazon Q as a tool specifically for developers, it might have some benefits over other generative AIs especially if it’s capable at the chore of programming in Assembly language. We’d love to hear anyone with real-world experience with this and whether it is truly worth the extra cost over something like Copilot or GPT 4. For any of these generative AI models, though, it’s probably worth trying them out while they’re in their early stages. Keep in mind that there’s a lot more than programming that can be done with some of them as well.