Amiga Programming In 2025 With AmiBlitz

August 10, 2025 by Tyler August 30 Comments

Having owned an Amiga microcomputer is apparently a little bit like having shaken hands with Shoggoth: no one can escape unchanged from the experience. Thirty-two years on, [Neil] at The Retro Collective remains haunted by the memories — specifically, the memory of BlitzBasic 2, an Amiga-specific programming language he never found the time to use. What better time to make a game for the Amiga than the year 2025 of the common era?

[Neil] takes us on a long journey, with more than a little reminiscing along the way. BlitzBasic may not have been the main programming language for the Amiga, but it was by no means the least, with a good pedigree that included the best-selling 1993 game Skidmarks. Obviously BlitzBasic was not a slow, interpreted language as one might think hearing “BASIC”. Not only is it a compiled language, it was fast enough to be billed as the next best thing to C for the Amiga, according to [Neil].

[Neil] wasn’t the only one whose dreams have been haunted by the rugose touch of the Amiga and its scquomose BlitzBasic language– you’ll find a version on GitHub called AmiBlitz3 that is maintained by [Sven] aka [honitas] to this day, complete with an improved IDE. The video includes a history lesson on the open-source AmiBlitz, and enough information to get you started.

For the vibe-coders amongst you, [Neil] has an excellent tip that you can use LLMs like ChatGPT to help you learn niche languages like this not by asking for code (which isn’t likely to give you anything useful, unless you’ve given it special training) but by requesting techniques and psudocode you can then implement to make your game. The LLM also proved a useful assistent for [Neil]’s excel-based pixel art workflow.

If you’re wondering why bother, well, why not? As [Neil] says, writing Amiga games is his version of a crossword puzzle. It may also be the only way to keep the dreams at bay. Others have taken to writing new operating systems or reproducing PCBs to keep vintage Amiga hardware alive. If some gather under the light of the full moon to chant “Ia! Ia! Commodore f’thagan”– well, perhaps we can thank them for Commodore for rising from the sunless depths of bankruptcy once again.

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SparcStation 1+ Finally Gets Attention

August 9, 2025 by Al Williams 12 Comments

We can’t throw stones. [Leaded Solder] picked up a SparcStation 1+ in 2018 and found it only produced illegal instruction errors. We’re sure he’s like us and meant to get back to it, and, instead, it sat on the bench, taking up space. You eventually have to move it, though, so seven years later, it was time for another go at it.

The first pass back in 2018 revealed that the machine had an interesting life. The full-sized hard drive was salvaged from an Apple computer. Removing the drive resolved the illegal instruction error. The drive seemed to work, but there was still nothing that suggested the machine would fully boot up. The next step was to try booting from a floppy, but that didn’t work either. The floppy cable had been surgically altered, again hinting this machine had seen some tough love.

Fast forward to 2025. This time, a Pi Pico-based SCSI emulator would stand in for the aging and suspect hard drive. Unfortunately, as noted, this machine has undergone some extensive and strange surgery. The power cable feeding the emulator had been rewired backwards, exposing the poor Pi Pico to 12 V, with predictable results. Luckily, it didn’t seem to phase the SparcStation.

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2025 One Hertz Challenge: The Real-Time Clock The VIC-20 Never Had

August 8, 2025 by Lewin Day 6 Comments

Like many early microcomputers, the Commodore VIC-20 did not come with an interna real-time clock built into the system. [David Hunter] has seen fit to rectify that with an add-on module as his entry to the 2025 One Hertz Challenge.

[David]’s project was inspired by a product that Hayes produced in the 1980s, which provided a serial-port based real-time clock solution for computers that lacked one on board. The heart of the project is an Arduino Uno, which itself uses a Dallas DS3231 RTC module to keep accurate time. [David] then drew from an IEC driver developed by [Lars Pontoppidan] for the MM2IEC project. This enables the Arduino to report the time to the VIC-20 via its IEC port.

The project is a neat way to provide a real-time clock source to programs written in Commodore BASIC. It’s also perfectly compatible with the IEC bus, so it can be daisy chained along with printers and disk drives without issue. [David] hasn’t tested it with a Commodore 64, but he suspects it should work just as well on that platform, too.

If you’ve ever wanted to build something clock-based for the VIC-20 but didn’t know how, this is a great piece of hardware to solve that problem. Meanwhile, you might find joy in reading about real-time clock hacks for other systems like the Raspberry Pi. Meanwhile, if you’re working on your own nifty timekeeping projects, don’t hesitate to let us know!

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

August 8, 2025 by Maya Posch 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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Happy Birthday 6502

August 4, 2025 by Jenny List 122 Comments

The MOS Technology 6502 is a microprocessor which casts a long shadow over the world of computing. Many of you will know it as the beating heart of so many famous 8-bit machines from the likes of Commodore, Apple, Acorn, and more, and it has retained enough success for a version to remain in production today. It’s still a surprise though, to note that this part is now fifty years old. Though there are several contenders for its birthday, the first adverts for it were in print by July 1975, and the first customers bought their chips in September of that year. It’s thus only fitting that in August 2025, we give this processor a retrospective.

The Moment Motorola Never Really Recovered From

A double page advert for the MOS 6501 and 6502, advertising its low cost and high performance. — The advert that started it all. MOS Technology, Public domain.

The story of the 6502’s conception is a fascinating tale of how the giants of the early mocroprocessor industry set about grappling with these new machines. In the earlier half of the 1970s, Chuck Peddle worked for Motorola, whose 6800 microprocessor reached the market in 1974. The 6800 was for its time complex, expensive, and difficult to manufacture, and Peddle’s response to this was a far simpler device with a slimmed-down instruction set that his contact with customers had convinced him the market was looking for: the 6502.

There’s a tale of Motorola officially ordering him to stop working on this idea, something he would later assert as such an abandonment of the technology that he could claim the IP for himself. Accompanied by a group of his Motorola 6800 colleagues, in the summer of 1974 he jumped ship for MOS Technology to pursue the design. What first emerged was the 6501, a chip pin-compatible with the 6800, followed soon after by the 6502, with the same core, but with an on-board clock oscillator. Continue reading “Happy Birthday 6502” →

Repairing An Obscure Apple II Clone

August 3, 2025 by Lewin Day 8 Comments

The Apple II was made in great numbers, as was the Commodore 64. But the Mimic Spartan? It was a weird Apple II clone that you needed a Commodore 64 to use. [ARC Javmaster] has found one of these obscure machines and has set about bringing it back to life. Check out the video below.

The story of the machine has been told online by one of the developers on the project, one [Brent Marykuca]. Basically, the Mimic Spartan was an Apple II clone that was intended to take advantage of a C64 as a host machine. It came in a beige box with a bunch of edge connectors and cables sticking out, and you were intended to nest it on the back of your C64 so it could hook up to all the ports. Then, you could use your machine as a C64 or an Apple II, or sort of… both… and even exchange data between both machines in some limited ways. There are also a few details of this obscure machine that have been collated by [Mike Naberezny], who is seeking the original disk that shipped with the machine when new.

It’s early days yet for [ARC Javmaster]’s efforts to restore the Mimic Spartan. Thus far, it’s had a clean and basic test. It was able to display a short line of text on a display before ceasing activity. A full boot hasn’t been achieved just yet, but we can’t wait to see where the resurrection efforts go next.

Back in the day, there were all kinds of Frankenstein computer cards that effectively put one kind of computer inside another. These days, you can condense an entire retro machine down to run on a single microcontroller.

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Rebuilt Batteries For The Cutest Clamshell At The Cafe

August 3, 2025 by Tyler August 21 Comments

Keeping retrocomputers going can be tricky enough, but when you’re talking retro laptops, the battery packs add an extra challenge. While one could simply live without the battery, that’s not going to give you the full retro experience. Replacement batteries are long out of stock, so what can one do? Well, one can check out this excellent tutorial by [lazd] on rebuilding an iBook G3 Clamshell battery.

Even if you don’t have this particular laptop, the general process is likely to be similar for PC laptops of similar vintage. (Which we still can’t believe is a whole quarter-century ago.) Luckily for retrocomputer enthusiasts, even Apple used standard 18650 cells in those bygone, halcyon days when computers were allowed to be more than a few atoms thick. They do need to be unprotected, flat-top cells, but that’s easy enough to source.

So it’s really a matter of carefully prying apart the casing (apparently it needs to be Apple-branded; aftermarket cases can’t survive being opened), removing the old batteries, and welding nickel tabs onto the new cells in the proper configuration. One thing that surprised us is that, apparently, Apple did not go in for balancing in those days — so make sure your cells are all in perfect condition and all equally charged before you start, or things won’t end nicely.

As always, battery orientation matters! The cells are welded into two sets in this Clamshell iBook battery.

Assuming you can pull it off (and your battery pack’s control chip has lasted the 300 moons since its manufacture), you’ll get a not-insignificant 5-hour battery run out of what’s sure to be the cutest clamshell computer at the cafe.

If you are repairing an iBook, while you’re at it, why not upgrade the RAM? You might even be able to fix the screen if it’s succumbing to the sadly-too-common vinegar syndrome.