Atari 7800:Game Incompatibilities

2600 Games with Issues

Although the Atari 7800 was designed to be backwards compatible with all Atari 2600 games, in actuality there are some 2600 games which will not boot or function properly on certain revisions of the 7800 hardware. Earlier consoles from the initial 1984 run and shipped during 1986 (consoles with an expansion port) seem to have the least issues, with later consoles having more problems. Listed below are some of the 2600 games which are known to have compatibility problems on later versions of the 7800.

• All Tigervision games are incompatible with all 7800s due to the dust cover posts poking out too far, preventing the game PCB from actually making contact with the cartridge port
• Arcadia Supercharger add-on games
• Robot Tank
• Space Shuttle
• The Activision Decathlon

Many of these incompatibilities can be fixed by removing a capacitor which forms part of a timing circuit, which was added to the system's motherboard during 1987. Removing this capacitor may also break compatibility with a few other 2600 games, namely Dark Chambers and Kung-Fu Master. Both of these games in particular have (arguably superior) ports on the 7800 however.

PAL Games with Issues on NTSC 7800

Note that the BIOS on NTSC 7800 consoles must be replaced with a different one that does not perform the encryption check, otherwise no PAL games will even boot. This issue does not apply to flash carts such as the Concerto as they clear the encryption check.

Also note that most PAL games will have the screen shifted down as they were reprogrammed to take advantage of the extra resolution PAL offers over NTSC. Some games that function correctly may also have slightly different colors due to the NTSC and PAL MARIA graphics chips having different color palettes.

These games were tested on a 1984-built NTSC 7800 using a Concerto flash cart.

Game Title	Issue	Severity
Ace of Aces	Rapidly flickering title screen, major graphical glitching during gameplay	Unplayable
Alien Brigade	Resets every few seconds on title screen	Unplayable
Ballblazer	Major graphical glitching, runs too slow	Severe
Barnyard Blaster	(No further testing performed due to lack of light gun)	?
Baseball	Entire screen flickers	Severe
Basketbrawl	No sound on title screen, plays too slow, major graphical glitching during gameplay	Severe
Centipede	Plays too slow	Moderate
Choplifter	Plays too slow, flickering colors during gameplay	Severe
Commando	Crashes to black screen after title screen	Unplayable
Crack'ed	Flickering colors during gameplay	Moderate
Crossbow	No issues other than the screen being shifted down	Minor
Dark Chambers	Graphical glitching when scrolling vertically	Moderate
Desert Falcon	Plays too slow, major graphical glitching	Severe
Dig Dug	Sound is too fast, gameplay is too slow, top half of screen flickers	Moderate
Donkey Kong	No issues other than the screen being shifted down	Minor
Donkey Kong Junior	No issues other than the screen being shifted down	Minor
Double Dragon	Boots to black screen	Unplayable
F-18 Hornet	Boots to vertical colored bars and droning sound	Unplayable
Fatal Run	Sound is too fast, flashing colors and major graphical corruption	Severe
Fight Night	Flickering colors, crashes when gameplay begins	Unplayable
Food Fight	Flickering graphical glitching, plays too slow	Moderate
Galaga	No issues other than the screen being shifted down	Minor
Hat Trick	No issues	N/A
Ikari Warriors	Flickering graphical corruption, plays far too slow	Severe
Impossible Mission	Flickering colors, crashes to black screen when entering a room	Unplayable
Jinks	Sound samples on title screen are just random noise, major graphical corruption	Severe
Joust	Crashes immediately, only displays copyright info on title screen	Unplayable
Karateka	Boots to black screen	Unplayable
Kung-Fu Master	Crashes to screen with corrupted graphics after title screen	Unplayable
Mario Bros.	No issues other than the screen being shifted down	Minor
Mat Mania Challenge	Corrupted title screen, droning sound during gameplay	Moderate
Mean 18 Ultimate Golf	Graphical corruption when anything moves, glitched sound	Moderate
Meltdown	Sound is too fast (No further testing done due to lack of light gun)	?
Midnight Mutants	No issues other than the screen being shifted down	Minor
Motor Psycho	Boots to black screen	Unplayable
Ms. Pac-Man	Screen is extremely jumpy, plays too slow	Severe
Ninja Golf	Severe graphical corruption during gameplay	Severe, almost unplayable
One-on-One Basketball	Flickering colors on game selection screen	Minor
Planet Smashers	No issues other than the screen being shifted down	Minor
Pole Position II	Flickering background, plays too slow	Minor
Scrapyard Dog	Crashes when gameplay begins	Unplayable
Sentinel	Corrupted graphics, flickering background (could not test further due to lack of light gun)	?
Super Huey UH-IX	No issues other than the screen being shifted down	Minor
Super Skateboardin'	Flickering background, plays too slow	Moderate
Title Match Pro Wrestling	No sound	Moderate
Tomcat: The F-14 Fighter Simulator	Flickering background, corrupted graphics on carrier, crashes when plane takes off	Unplayable
Tower Toppler	Boots to black screen	Unplayable
Xenophobe	Crashes at title screen	Unplayable
Xevious	Graphical glitching at top of screen, uneven frame rate	Moderate

NTSC Games with Issues on PAL 7800

All NTSC games have some graphical glitches on the botttom of the screen due to the higher resolution of the PAL MARIA. Some games that function correctly may also have slightly different colors due to the NTSC and PAL MARIA graphics chips having different color palettes.

These games were tested on a 1991-built PAL 7800 using a RetroHQ 7800GD flash cart.

Game Title	Issue	Severity
Ace of Aces	Rapidly flickering on the title screen and during gameplay	Unplayable
Asteroids	Runs way too fast to be playable and has some graphical glitches mid-screen at times	Unplayable
Ballblazer	Some graphical glitching on the top screen. Runs for a bit but crashes randomly	Unplayable
Donkey Kong	Runs way too fast to be playable	Unplayable
Donkey Kong Junior	Runs way too fast to be playable	Unplayable
Double Dragon	Crashes to black screen after the title screen	Unplayable
Mario Bros.	Runs way too fast to be playable	Unplayable
Pole Position II	Flickering background, plays too slow	Minor