A Chess AI In Only 4K Of Memory

June 23, 2023 by Bryan Cockfield 22 Comments

The first computer to ever beat a reigning chess world champion didn’t do so until 1996 when a supercomputer built by IBM beat Garry Kasparov. But anyone who wasn’t a chess Grandmaster could have been getting beaten by chess programs as early as 1979 when Atari released one of the first ever commercially-available chess video games for the Atari 2600. The game was called Video Chess and despite some quirky gameplay it is quite impressive that it was able to run on the limited Atari hardware at all as [Oscar] demonstrates.

The first steps of getting under the hood of this program involved looking into the mapping of the pieces and the board positions in memory. After analyzing some more of the gameplay, [Oscar] discovered that the game does not use trees and nodes to make decisions, likely due to the memory limitations, but rather simulates the entire game and then analyzes it to determine the next step. When the game detects that there are not many pieces left on the board it can actually increase the amount of analysis it does in order to corner the opposing king, and has some unique algorithms in place to handle things like castling, finishing the game, and determining valid movements.

Originally it was thought that this engine couldn’t fit in the 4K of ROM or work within the 128 bytes of system memory, and that it was optimized for the system after first developing a game with some expanded capabilities. The game also has a reputation for making illegal moves in the higher difficulty settings although [Oscar] couldn’t reproduce these bugs. He also didn’t get into any of the tricks the game employed just to display all of the pieces on the screen. The AI in the Atari game was a feat for its time, but in the modern world the Stockfish open-source chess engine allows for a much more expanded gameplay experience.

The MouSTer Adapter Now Has Amiga Scroll Support

February 16, 2023 by Lewin Day 6 Comments

The MouSTer is a device that enables modern USB HID mice to be used on various retro computers. The project has been through its ups and downs over years, but [drygol] is here to say one thing: rumors of the MouSTers demise have been greatly exaggerated. Now, the project is back and better than ever!

The team has been hard at work on quashing bugs and bringing new features to bear. The headline is that the MouSTer project will now offer mouse wheel support for Amiga users. This is quite the coup, as mouse wheels were incredibly obscure until the late 90s. Now, users of Commodore’s finest machines will be able to scroll with abandon with modern HID mice.

While the progress is grand, much is still left to be done. Despite the name, the MouSTer was never intended to solely serve Atari users. Future goals involve adding support for ADB mice for retro Macs, DB9 mouse support for even-older Apple machines, and DB9 mouse support for older PCs. The team is eager for there to be one MouSTer to rule them all, so to speak, and hopes to make the ultimate retro computer mouse adapter to serve as many purposes as possible.

We first looked at the MouSTer back in 2020, and it’s great to see how far it’s come.

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Combat Gets A Computer Controlled Opponent

August 1, 2022 by Tom Nardi 11 Comments

If you ever spent some time playing on the Atari 2600, there’s an excellent chance you went through a few rounds of Combat. The two-player warfare game not only came with the console but was actually one of the more technically impressive titles for the system, offering nearly 30 variations of the core head-to-head gameplay formula.

But unfortunately, none of those modes included single player. That is, until [Nick Bild] got on the case. While some concessions had to be made, he has succeeded where the original developers failed, and added a computer-controlled enemy to Combat. What’s more, the game still runs on the stock 2600 hardware — no emulator tricks required. The true aficionados can marvel at the snippets of source code he’s provided, but the rest of us can just watch the video below the break and marvel at the accomplishment.

If you’ve never worked on such a constrained system, this might not seem like a big deal. But [Nick] does a great job of explaining not just what he did, but why it was so hard to pull off in the first place. For example, the console has no video buffer, so everything needs to be done during the VBLANK period where the game doesn’t need to be drawing to the screen. Unfortunately that didn’t give him enough free cycles, so he had to split his code up to run across three frames instead of just one. That mean’s the original game logic is now only running 27 frames out of the 30 per second, but he says you can’t really tell in practice.

That said, some cuts had to be made. He needed to remove the surprisingly complex engine sounds to free up some resources, and had to bump the 2 KB cartridge up to 4 KB to hold the new code and data. Turns out the 2600 could handle far larger cartridges via bank switching though, so this wasn’t actually a problem.

Given its age and limited capabilities compared to more modern consoles, you might think the Atari 2600 would be little more than a footnote in gaming history. But there’s a devoted group of folks who enjoy squeezing everything they can out of the system’s 45-year-old hardware which leads to labors of love like this one.

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Atari At 50: The Story Of Our Lives

June 27, 2022 by Jenny List 14 Comments

It’s been a year of anniversaries, what with the 40th birthday of both the Commodore 64 and the Sinclair ZX Spectrum. But there’s another anniversary that in a sense tops them all, today marks 50 years since Nolan Bushnell and Ted Dabney incorporated Atari Inc, a name that will forever be synonymous with the development of the computer game industry. PC Magazine have marked the event with a retrospective, an affectionate look at the progress from Spacewar! coin-ops to the unsuccessful Jaguar console of the 1990s, and it pulls no punches over the lacklustre management that oversaw its decline in later years.

For us the high points of the Atari story were the VCS console and the ST line of computers, which probably best represent the brand’s successes in Europe where this is being written. It’s with something of a wince that we remember watching an Atari Lynx advert in a British cinema, in which the laugh came when the teenager-unaffordably high price was revealed. At least diehard Atari fans can take solace in that by then Commodore was equally being run into the ground.

One criticism PC Magazine makes is that the current Atari incarnation is doing little beyond rehashing past glories, and perhaps they’re right. Last year we covered their release of some new cartridges for the VCS.

Introducing The Universal Atari Keyboard Case

March 10, 2022 by Lewin Day 3 Comments

[10p6] wondered what it would be like if Atari had used a standardized keyboard across its 16-bit and 32-bit computer lines in 1985. Imagination is fun, but building things is even better, and thus they set out to create such a thing. Enter the Universal Atari Keyboard Case.

The case design is flexible, and can accept a keyboard from models including the Atari ST and Falcon. The keyboard can then be used with an Atari Mega, TT, or desktop-style Atari computers without mods. It also brings modern peripherals to bear on these old Atari platforms, enabling the use of modern USB mice while also using the two onboard joystick ports. Power and floppy LEDs are present, but subtly hidden beneath the case, only becoming visible when illuminated. It also includes 5-watt stereo speakers for getting the best out of the Atari’s sound hardware.

The final part, a full 473mm long, was 3D printed in resin for a high-quality surface finish. The results are so good it almost looks like a genuine factory keyboard.

If you’re regularly playing with your vintage Atari machines and you want a great keyboard to use with them, this could be the design for you. [10p6] has promised to soon upload the design files to Thingiverse for those eager to replicate the work.

We’ve also seen retro Atari keyboard converted to work with modern machines. Video after the break. Continue reading “Introducing The Universal Atari Keyboard Case” →

Reverse Engineering The SEGA Mega Drive

January 19, 2022 by Bryan Cockfield 16 Comments

With the widespread adoption of emulators, almost anyone can start playing video games from bygone eras. Some systems are even capable of supporting homebrew games, with several having active communities that are still creating new games even decades later. This ease of programming for non-PC platforms wasn’t always so easy, though. If you wanted to develop games on a now-antique console when it was still relatively new, you had to jump through a lot of hoops. [Tore] shows us how it would have been done with his Sega Mega Drive development kit that he built from scratch.

While [Tore] had an Atari ST, he wanted to do something a little more cutting edge and at the time there was nothing better than the Mega Drive (or the Genesis as it was known in North America). It had a number of features that lent the platform to development, namely the Motorola 68000 chip that was very common for the time and as a result had plenty of documentation available. He still needed to do quite a bit of reverse engineering of the system to get a proper dev board running, though, starting with figuring out how the cartridge system worked. He was able to build a memory bank that functioned as a re-writable game cartridge.

With the hard parts out of the way [Tore] set about building the glue logic, the startup firmware which interfaced with his Atari ST, and then of course wiring it all together. He was eventually able to get far enough along to send programs to the Mega Drive that would allow him to control sprites on a screen with the controller, but unfortunately he was interrupted before he could develop any complete games. The amount of research and work to get this far is incredible, though, and there may be some helpful nuggets for anyone in the homebrew Mega Drive community today. If you don’t want to get this deep into the Mega Drive hardware, though, you can build a cartridge that allows for development on native Sega hardware instead.

An Atari 130XE's keyboard made mechanical with Kailh box pinks and 3D-printed keyswitch stems.

Atari 130XE Keyboard Now Goes Clack

December 12, 2021 by Kristina Panos 10 Comments

Performing a resto-mod on a beloved piece of childhood technology can be quite a ride. In [Bertrand]’s case, it was the keyboard to their Atari 130XE. Although it has those cool double-shot keycaps, they’re hiding a crappy membrane underneath that could really benefit from a mechanical upgrade. Relax — the membrane part was broken.

[Bertrand] designed and printed some new stems for Kailh box pinks that can accept both of the two known variants instead of the standard Cherry MX receptacle. He also made a new PCB (natch) and a keyboard adapter to replace the membrane interface, and had a steel keyswitch plate custom cut. The so-called Atari 130MX mod can be used with an Atari 130XE computer, or as a regular keyboard for a PC if you solder in a Pico.

[Bertrand] says that this labor of love was meant to be reproduced and told us that for some folks in the Atari community, it’s already on like Donkey Kong. If you’re going to attempt this mod, know that filament printers won’t work well at all for these tiny and precise parts. [Bertrand] printed the stems on an Elegoo with a resolution of 1/20 mm (50 micrometers). On the bright side, old-new stock Atari keycaps are not that hard to find. Check it out after the break.

We love to see vintage keyboards get modern upgrades. Did you see the nuclear missile silo keyboard/trackball combo? When we read that it came from ebay, our wallet took itself to DEFCON 1.

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