basic

105 Articles

Microsoft BASIC For 6502 Is Now Open Source

September 4, 2025 by 29 Comments

An overriding memory for those who used 8-bit machines back in the day was of using BASIC to program them. Without a disk-based operating system as we would know it today, these systems invariably booted into a BASIC interpreter. In the 1970s the foremost supplier of BASIC interpreters was Microsoft, whose BASIC could be found in Commodore and Apple products among many others. Now we can all legally join in the fun, because the software giant has made version 1.1 of Microsoft BASIC for the 6502 open source under an MIT licence.

This version comes from mid-1978, and supports the Commodore PET as well as the KIM-1 and early Apple models. It won’t be the same as the extended versions found in later home computers such as the Commodore 64, but it still provides plenty of opportunities for retrocomputer enthusiasts to experiment. It’s also not entirely new to the community, because it’s a version that has been doing the rounds unofficially for a long time, but now with any licensing worries cleared up. A neat touch can be found in the GitHub repository, with the dates on the files being 48 years ago.

We look forward to seeing what the community does with this new opportunity, and given that the 50-year-old 6502 is very much still with us we expect some real-hardware projects. Meanwhile this isn’t the first time Microsoft has surprised us with an old product.

Header image: Michael Holley, Public domain.

Exploring The TRS-80’s Color BASIC’s Random Number Function

August 8, 2025 by 6 Comments

Although these days we get to tap into many sources of entropy to give a pretty good illusion of randomness, home computers back in the 1980s weren’t so lucky. Despite this, their random number generators were good enough for games and such, as demonstrated by the [CoCo Town] YouTube channel.

The CoCo is the nickname for the TRS-80 Color Computer, which despite its name, shares absolutely nothing with the TRS-80. Its BASIC version is called Color BASIC, which like many others was based on Microsoft BASIC, so the video’s description should be valid for many other BASIC versions as well. In the video we’re first taken through a basic summary of what the floating point format is all about, before running through an example of the algorithm used by Color BASIC for its RND function, using a test program written in Color BASIC.

As described in the video, the used algorithm appears to be the linear congruential generator, which is a pseudo-random generator that requires minimal resources from the hardware it runs on. Of course, its main disadvantage is that it will fairly rapidly begin to repeat itself, especially with a limited number of output bits. This makes it a decent choice even today for something like simple game logic where you just want to get some variation without aiming for cryptographically secure levels of randomness.

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A Proper Computer For A Dollar?

August 1, 2025 by 49 Comments

When a tipster came to us with the line “One dollar BASIC computer”, it intrigued us enough to have a good look at [Stan6314]’s TinyBasRV computer. It’s a small PCB that forms a computer running BASIC. Not simply a microcontroller with a serial header, this machine is a fully functioning BASIC desktop computer that takes a PS/2 keyboard and a VGA monitor. Would that cheap price stand up?

The board uses a CH32 microcontroller, a RISC-V part that’s certainly very cheap indeed and pretty powerful, paired with an I2C memory chip for storage. The software is TinyBASIC. There’s some GPIO expandability and an I2C bus, and it’s claimed it can run in headless mode for a BASIC program to control things.

We haven’t added up all the parts in the BoM to check, but even if it’s not a one dollar computer it must come pretty close. We can see it could make a fun project for anyone. It’s certainly not the only small BASIC board out there, it’s got some competition.

Thanks [Metan] for the tip.

Behind The Bally Home Computer System

June 28, 2025 by 9 Comments

Although we might all fundamentally recognize that gaming consoles are just specialized computers, we generally treat them, culturally and physically, differently than we do desktops or laptops. But there was a time in the not-too-distant past where the line between home computer and video game console was a lot more blurred than it is today. Even before Microsoft entered the scene, companies like Atari and Commodore were building both types of computer, often with overlapping hardware and capabilities. But they weren’t the only games in town. This video takes a look at the Bally Home Computer System, which was a predecessor of many of the more recognized computers and gaming systems of the 80s.

At the time, Bally as a company was much more widely known in the pinball industry, but they seemed to have a bit of foresight that the computers used in arcades would eventually transition to the home in some way. The premise of this console was to essentially start out as a video game system that could expand into a much more full-featured computer with add-ons. In addition to game cartridges it came with a BASIC interpreter cartridge which could be used for programming. It was also based on the Z80 microprocessor which was used in other popular PCs of the time, so in theory it could have been a commercial success but it was never able to find itself at the top of the PC pack.

Although it maintains a bit of a cult following, it’s a limited system even by the standards of the day, as the video’s creator [Vintage Geek] demonstrates. The controllers are fairly cumbersome, and programming in BASIC is extremely tedious without a full keyboard available. But it did make clever use of the technology at the time even if it was never a commercial success. Its graphics capabilities were ahead of other competing systems and would inspire subsequent designs in later systems. It’s also not the last time that a video game system that was a commercial failure would develop a following lasting far longer than anyone would have predicted.

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Genetic Algorithm Runs On Atari 800 XL

February 21, 2025 by 7 Comments

For the last few years or so, the story in the artificial intelligence that was accepted without question was that all of the big names in the field needed more compute, more resources, more energy, and more money to build better models. But simply throwing money and GPUs at these companies without question led to them getting complacent, and ripe to be upset by an underdog with fractions of the computing resources and funding. Perhaps that should have been more obvious from the start, since people have been building various machine learning algorithms on extremely limited computing platforms like this one built on the Atari 800 XL.

Unlike other models that use memory-intensive applications like gradient descent to train their neural networks, [Jean Michel Sellier] is using a genetic algorithm to work within the confines of the platform. Genetic algorithms evaluate potential solutions by evolving them over many generations and keeping the ones which work best each time. The changes made to the surviving generations before they are put through the next evolution can be made in many ways, but for a limited system like this a quick approach is to make small random changes. [Jean]’s program, written in BASIC, performs 32 generations of evolution to predict the points that will lie on a simple mathematical function.

While it is true that the BASIC program relies on stochastic methods to train, it does work and proves that it’s effective to create certain machine learning models using limited hardware, in this case an 8-bit Atari running BASIC. In previous projects he’s also been able to show how similar computers can be used for other complex mathematical tasks as well. Of course it’s true that an 8-bit machine like this won’t challenge OpenAI or Anthropic anytime soon, but looking for more efficient ways of running complex computation operations is always a more challenging and rewarding problem to solve than buying more computing resources.

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Basically, It’s BASIC

February 10, 2025 by 36 Comments

The BASIC language may be considered old-hat here in 2025, and the days when a computer came as a matter of course with a BASIC interpreter are far behind us, but it can still provide many hours of challenge and fun. Even with our love of all things 8-bit, though, we’re still somewhat blown away by [Matthew Begg]’s BASIC interpreter written in 10 lines of BASIC. It’s an entry in the BASIC 10-liner competition, and it’s written to run on a Sinclair ZX Spectrum.

The listing can be viewed as a PNG file on the linked page. It is enough to cause even the most seasoned retrocomputer enthusiasts a headache because, as you might expect, it pushes the limits of the language and the Sinclair interpreter.  It implements Tiny Basic as a subset of the more full-featured BASICs, and he’s the first to admit it’s not fast by any means. He gives a line-by-line explanation, and yes, it’s about as far away from the simple Frogger clones we remember bashing in on our Sinclairs as it’s possible to get.

We love it that there are still boundaries to be pushed, even on machines over four decades old, and especially that this one exceeds what we thought was a pretty good knowledge of Sinclair BASIC. Does this language still have a place in the world? We always look forward to the BASIC 10-liner competition.

Header: background by Bill Bertram, CC BY-SA 2.5.

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.