atari st

13 Articles

Reverse Engineering The SEGA Mega Drive

January 19, 2022 by 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 ST running a campground reservation system

Atari ST Still Manages Campground Reservations After 36 Years

October 6, 2021 by 40 Comments

“Don’t fix it if it ain’t broke”. That’s what we guess [Frans Bos] has been thinking for the past few decades, as he kept using his Atari ST to run a booking system for the family campground. (Video, embedded below.)

Although its case has yellowed a bit, the trusty old machine is still running 24/7 from April to October, as it has done every year since 1985. In the video [Frans] demonstrates the computer and its custom campground booking system to [Victor Bart].

To be exact, we’re looking at an Atari 1040STF, which runs on a 68000 CPU and has one full megabyte of RAM: in fact it was one of the first affordable machines with that much memory. Output is through a monochrome display, which is tiny compared to the modern TFT standing next to it, but was apparently much better than the monitor included with a typical DOS machine back in the day.

Since no campground management software was available when he bought the computer, [Frans] wrote his own, complete with a graphical map showing the location of each campsite. Reservations can be made, modified and printed with just a few keystrokes. The only concession to the modern world is the addition of a USB drive; we can imagine it was becoming difficult to store and exchange data using floppy disks in 2021.

We love seeing ancient hardware being actively used in the modern world: whether it’s floppy disks inside a Boeing 747 or an Amiga running a school’s HVAC system. Thanks to [Tinkerer] for the tip.

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Detective Work Recovers Atari ST ASIC Designs

September 5, 2018 by 28 Comments

[Christian Zietz] wanted to know more about the Atari ST. He found information online from newer Atari machines like the Falcon030 and the Jaguar, but couldn’t find much else. While looking through some archives of old disk images from the Atari headquarters, he found a folder marked “Drawings\4118.” With some detective work and emulation of an old operating system, he was able to recover the schematics for the ST-4118 video shifter ASIC (Application-Specific Integrated Circuit).

Unfortunately, this appeared to be a chip for the unreleased Atari Panther video game console. However, it did show the way to how these older schematics were readable. [Christian] continued searching and found some floppy disk images that were a bit unusual. They didn’t have a proper file system but had been created by a backup program called FastBack for MS-DOS.

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Bring A Modern Mouse To An Atari ST

January 23, 2017 by 35 Comments

Human input devices are a consumable on our computers today. They are so cheap and standardised, that when a mouse or a keyboard expires we don’t think twice, just throw it away and buy another one. It’ll work for sure with whatever computer we have, and we can keep on without pause.

On earlier machines though, we might not be so lucky. The first generation of computers with mice didn’t have USB or even PS/2 or serial, instead they had a wide variety of proprietary mouse interfaces that usually carried the quadrature signals direct from the peripheral’s rotary sensors. If you have a quadrature mouse that dies then you’re in trouble, because you won’t easily find a new one.

Fortunately there is a solution. In the intervening decades the price of computing power has fallen to the extent that you can buy a single board computer with far more than enough power to interface with a standard USB mouse and emulate a quadrature mouse all at the same time. This was exactly the solution [Andrew Armstrong] took to provide a replacement mouse for his Atari ST, he used a Raspberry Pi as both USB host and quadrature mouse emulator (YouTube link) through its GPIOs.

He’s put together a comprehensive description of his work in the video we’ve placed below the break, meanwhile if you’d like to have a go yourself you’ll find all you need to know in his GitHub repository.

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An Atari ST Rises From The Ashes

June 9, 2016 by 19 Comments

We’ve all made rash and impulsive online purchasing decisions at times. For [Drygol] the moment came when he was alerted to an Atari 1040STe 16-bit home computer with matching monitor at a very advantageous price.

Unfortunately for him, the couriers were less than careful with his new toy. What arrived was definitely an ST, but new STs didn’t arrive in so many pieces of broken ABS. Still, at least the computer worked, so there followed an epic of case repair at the end of which lay a very tidy example of an ST.

He did have one lucky break, the seller had carefully wrapped everything in shrink-wrap so no fragments had escaped. So carefully applying acetone to stick the ABS together he set to work on assembling his unexpected 3D jigsaw puzzle. The result needed a bit of filler and some sanding, but when coupled with a coat of grey paint started to look very like an ST case that had just left the factory. Adding  modern SD card and USB/Ethernet interfaces to the finished computer delivered a rather useful machine as you can see in the video below the break.
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Suska Open Source Atari ST

January 7, 2010 by 15 Comments

Got a special place in your heart for Atari computing? Now you can quench that need using new hardware. The Suska project has achieved complete hardware emulation of the Atari ST using an FPGA. The project’s progress tracker shows implementation of the major chips at 100%. They are running EmuTOS, an Atari emulator, as the operating system because running the original would violate copyright. The chip used is an Altera Cyclone III. You could load up the code on your own hardware but judging from the number of connections needed it might be less of a headache to buy a board from these guys.

[Thanks Erik]