Porting atari 5200 to atari 7800

[JAK327]

Is there away to port atari 5200 games to the atari 7800? I would like to see miner 2049er and bbsb. Also what about arcade games like super zaxxon, bagman, tempest and countless others. Any information will be great.

[Enigmus]

Other than completely recoding most, if not all assets of the game, no.

[buzz_n64]

Even if it were possible, it would be an inferior port. The Atari 5200 had a superior sound chip, 4 player options on some games, and some games utilized the vast amount of buttons the Atari 5200 joystick offered. I have not looked into those two games specifically, but I would say stick with the 5200 version and system. You can however, port Atari 400/800/XL computer games to the Atari 5200.

[7th lutz]

Tempest is one of the Atari 7800 games that Atari 7800 homebrew developer Grooveybee has in development for the 7800. I really don't know when the game will be completed. He has a lot of 7800 game projects for the regular 7800 and the Atari 7800 Expansion Module including a 2 player Bomberman style game called Fruitarian.

Here is a link the 7800 homebrew author 7800 games in development page: http://www.atariage.com/forums/user/21935-groovybee/ . It is under Grooveybee's about me tab.

What I can tell you is the Atari 5200 has more ram than the Atari 7800 has and a better sound chip. The 7800 has the same sound chip as the Atari 2600 despite the fact the 7800 has a different cpu than the 2600. The Atari 7800 is capable of has higher rom game cartridges than the 5200 can without bank switching. Those two things would make Atari 5200 ports on an Atari 7800 downgraded, unlike the Atari 7800 Expansion module.

The Atari 7800 Expansion module will have an easy time to port Atari 5200 games due to the the specs the Atari 7800 expansion module has. The nature of the Atari 7800 expansion module specs actually makes it capable of doing better Atari Xl/XE game ports than a regular 7800 could besides doing advanced arcade games from the mid to late 1980's.

What the the 7800 Expansion has is an additional 128k of ram. Atari 5200 sound chip, Yamaha YM2151 sound chip, built in high score cart, port for a future detachable keyboard, and SIO port for potential future use of Atari 8bit computer peripherals such as Disk Drives, Printers and Modems.

The Yamaha YM2151 sound chip the Atari 7800 Expansion Module has is one that you find in a lot of arcade games from Sega, Atari Games, Konami, and Capcom back in the 1980's including Jackal, Contra, and Marble Madness. The Yamaha YM2151 sound chip also is found in Sharp X1 computers, Sharp X68000 computers, and an expansion unit for MSX computer.

[Greg2600]

Still doesn't change the fact that porting a 5200 game to the 7800 would require a ton of coding, so much so that you're basically doing it from scratch. It's not as easy as porting XL to the 5200. Most 7800 games were ported back then to the Atari XE/XEGS anyhow, and the XE-only games were pretty bad, you wouldn't want to bother to convert to the 7800.

[GroovyBee]

Other than completely recoding most, if not all assets of the game, no.

I don't agree. If the game in question uses one of the 160 pixel across modes then it would be a good candidate for conversion.

Still doesn't change the fact that porting a 5200 game to the 7800 would require a ton of coding, so much so that you're basically doing it from scratch.

Not necessarily. When I did Tempest from the BBC micro it didn't take long to get something working on the the 7800. As soon as I reverse engineered the code, worked around the self modifying parts, replaced the line drawing code and pointed the code at the frame buffer (the 7800 hardware was initialised before the entry point in the BBC micro code was called) it pretty much burst into life. However it still needs a ton of work to get it into a releasable form (mainly due to the scan line differences between the machines).

The hardest part in a cross port is figuring out what the code is supposed to do during the reverse engineering process. In that process you need to get a version of the code that can be relocated anywhere in memory to allow for memory map differences with the RAM and ROM. A good technical knowledge of both machines helps enormously too.