Sega’s AI Computer Embraces The Artificial Intelligence Revolution

Recently a little-known Sega computer system called the Sega AI Computer was discovered for sale in Japan, including a lot of the accompanying software. Although this may not really raise eyebrows, what’s interesting is that this was Sega’s 1986 attempt to cash in on Artificial Intelligence (AI) hype, with a home computer that could handle natural language. Based on the available software and documentation, it looked to be mostly targeted at younger children, with plans to launch it in the US later on, but ultimately it was quietly shelved by the end of the 1980s.

Part of the Sega AI Computer's mainboard, with the V20 MPU and ROMs.
Part of the Sega AI Computer’s mainboard, with the V20 MPU and ROMs.

The computer system itself is based around the NEC v20 8088-compatible MPU with 128 kB of RAM and a total of 512 kB of ROM, across multiple chips. The latter contains not only the character set, but also a speech table for the text to speech functionality and the Prolog-based operating system ROM. It is this Prolog-based environment which enables the ‘AI’ functionality. For example, the ‘diary’ application will ask the user a few questions about their day, and writes a grammatically correct diary entry for that day based on the responses.

On the system’s touch panel overlays can be used through cartridge or tape-based application to make it easy for children to interact with the system, or a full-sized keyboard can be used instead. All together, 14 tapes and 26 cartridges (‘my cards’) had their contents dumped, along with the contents of every single ROM in the system. The manual and any further documentation and advertising material that came with the system were scanned in, which you can peruse while you boot up your very own Sega AI Computer in MAME. Mind that the MAME system is still a work in progress, so bugs are to be expected. Even so, this is a rare glimpse at one of those aspirational systems that never made it out of the 1980s.

Can An 8-Bit Light Gun Work On A Modern TV?

It’s an accepted part of retro gaming lore, that 8-bit consoles perform best when used with an original CRT TV. One of the reason for this is usually cited as being because the frame buffer and scaler circuit necessary for driving an LCD panel induces a delay not present on the original, and in particular this makes playing games which relied on a light gun impossible to play. It’s a subject [Nicole Branagan] takes a look at, and asks whether there are any ways to use a classic light gun with a modern TV.

Along the way we’re treated to an in-depth look at the tech behind light gun games, how the gun contained a photodiode which on the NES was triggered by the brief showing of a frame with a white square where the target would sit, and on the Sega consoles by a white screen with an on-board timer counting the screen position at which the gun was aimed.

The conclusion is that the delay means you won’t be playing Duck Hunt or Hogan’s Alley on your 4K TV, but interestingly, all is not lost. There are modified versions of the games that take account of the delay, or an interesting lightgun emulator using a WiiMote. We’d be happy at playing either way, just as long as we can take pot-shots at the annoying Duck Hunt dog.

Light gun image: Evan-Amos, Public domain.

A Cycle-Accurate Sega Genesis With FPGA

The Field-Programmable Gate Array (FPGA) is a powerful tool that is becoming more common across all kinds of different projects. They are effectively programmable hardware devices, capable of creating specific digital circuits and custom logic for a wide range of applications and can be much more versatile and powerful than a generic microcontroller. While they’re often used for rapid prototyping, they can also recreate specific integrated circuits, and are especially useful for retrocomputing. [nukeykt] has been developing a Sega Genesis clone using them, with some impressive results.

The Sega Genesis (or Mega Drive) was based around the fairly common Motorola 68000 processor, but this wasn’t the only processor in the console. There were a number of coprocessors including a Z80 and several chips from Yamaha to process audio. This project reproduces a number of these chips which are cycle-accurate using Verilog. The chips were recreated using images of de-capped original hardware, and although it doesn’t cover every chip from every version of the Genesis yet, it does have a version of the 68000, a Z80, and the combined Yamaha processor working and capable of playing plenty of games.

The project is still ongoing and eventually hopes to recreate the rest of the chipset using FPGAs. There’s also ongoing testing of the currently working chips, as some of them do still have a few bugs to work out. If you prefer to take a more purist approach to recreating 90s consoles, though, we recently featured a project which reproduced a Genesis development kit using original hardware.

Thanks to [Anonymous] for the tip!

DOOM Ported To Sega Naomi Arcade Hardware

Porting DOOM to new hardware and software platforms is a fun pastime for many in the hacker scene. [DragonMinded] noticed that nobody had ported the game to the Sega Naomi arcade hardware, and set about doing so herself.

The port builds on work by [Kristoffer Andersen] who built a framebuffer port of DOOM previously. It’s available pre-compiled, complete with the shareware WAD for those eager to load it up on their own Naomi arcade cabinets.

Unlike some limited ports that only give the appearance of a functional version of DOOM, this port is remarkably complete. Loading, saving, and options menus are all present and accounted for, as well as directional sound and even WAD auto-discovery. With that said, there’s only 32 KB of space for save games on the Naomi hardware, so keep that in mind if you find yourself playing regularly.

We love a good DOOM port, whether it’s on an arcade machine, an old forgotten Apple OS, or even a UFI module.

Continue reading DOOM Ported To Sega Naomi Arcade Hardware”

Mortal Kombat Stand Up Arcade machines

Mortal Kombat ROM Hack Kontinues Arcade Legacy

September 13th 1993, colloquially known as Mortal Monday, became as dividing line in the battle for 16-bit supremacy. The mega popular arcade game Mortal Kombat was ported to Super Nintendo and Sega Genesis consoles, and every fanboy and fangirl had an opinion on which version truly brought the hits. The Super Nintendo version opted to remove the blood and gore in an attempt to preserve the company’s family-friendly image. While the Sega Genesis merely locked the game’s more violent content behind a cheat code that so many fans learned by heart, ABACABB. Nintendo’s decision to censor Mortal Kombat on their console pushed public opinion in favor of the Sega Genesis version being superior, though it was clear that corners were cut in order to squeeze it onto a cartridge. Recently a group of developers led by [Paulo] sought to restore the Genesis version to its full potential with a ROM hack they’re calling Mortal Kombat Arcade Edition.

Mortal Kombat Arcade Edition is the sort of ROM hack where every facet of the game has been retouched. All sorts of sound effects and animations that were omitted in the 1993 translation to the Genesis have now been restored in higher quality. Every fighter’s look was remastered to more closely match the arcade presentation complete with move timing tweaks. Secret characters like Reptile, Noob Saibot, and Ermac are all playable, plus all the character bios from the arcade game’s attract mode make an appearance. An SRAM save feature was implemented in order to save high scores, and for an additional dose of authenticity there’s even a “DIP switch” configuration screen where you can set it to free play.

This ROM hack comes as an IPS patch that can be applied to a legitimate dump of the user’s Sega Genesis or Mega Drive cartridge. The site hosting the Mortal Kombat Arcade Edition patch features an online IPS patching tool called Rom Patcher JS that makes the patching process more convenient for those attached to their browser. The patched ROM can then be enjoyed in the user’s favorite emulator of choice, though running it on original hardware via a ROM cart is also possible (even encouraged). Considering the limitations of the Sega Genesis’ color palette the revamped look of Mortal Kombat Arcade Edition is all the more impressive. It just goes to show you that Genesis still does!

Not ready to FINISH HIM? Check out this countertop arcade build featuring some Mortal Kombat II art, or marvel at the incredible effort that went into creating the Knights of the Round ROM hack known as Warlock’s Tower.

Continue reading Mortal Kombat ROM Hack Kontinues Arcade Legacy”

Reverse Engineering The SEGA Mega Drive

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.

The Dreamcast Legacy

The Dreamcast is a bit of an odd beast. Coming on the heels of the unpopular Sega Saturn, the Dreamcast was meant to be a simple console built with off-the-shelf parts and released in late 1998. The Nintendo 64 was already tough competition (1996). Ultimately, the Dreamcast fell out of the public eye in the early 2000s as the Playstation 2, Xbox, and Gamecube were all released with incredible fanfare just a few years later. In some sense, Sega’s last console is a footnote in gaming history.

But despite not achieving the success that Sega hoped for, the Dreamcast has formed a small cult following, because as we know, nothing builds a cult-like following like an untimely demise. Since its release, it has gained a reputation for being ahead of its time. It was the first console to include a modem for network play and an easy storage solution for transferring game data between consoles via the VMUs that docked in the controllers. It had innovative and classic games such as Crazy TaxiJet Set RadioPhantasy Star Online, and Shenmue. Microsoft even released a version of Windows CE with DirectX allowing developers to port PC games to the console quickly.

We see our fair share of console hacks here on Hackaday, but what is the ultimate legacy of the Dreamcast? How did it come to be? What happened to it, and why did so much of Sega’s hopes ride on it? Continue reading “The Dreamcast Legacy”