Robot Tank incompatible with the 7800?

[Max-T]

Wasn't sure whether to post this in this forum but... Robot Tank was always one of my favorite VCS games when I was a kid. I recently came across a boxed copy of it, and there is a little sticker on the box warning that that it is not for use with the 7800 system.

 

Anyone know why? I thought the 7800 was completely backwards-compatible. Not a big deal, just something I thought was curious. Needless to say, I didn't want to stick the cart into my ProSystem to try and prove the box wrong!

[fsuinnc]

I'm sure it's technical and I don't know the reasons but Funky Fish and Pleiades have the same problem.

Strange.

[Max-T]

Hmmm, I wonder if those games use a weird bankswitching system. I know I've seen a list of games' bankswitching schemes somewhere around. I'll try to find it and see if that's what it is. Thanks for the other clues!

[+DamonicFury]

The Robot Tank/7800 issue is complicated, and I'm sure someone can explain it better than I can, but I do know that not all 7800's have the problem... and also not all Robot Tank cartridges have the problem! I have two Robot Tank carts, both of which work fine in my 2600, but one will not work with my 7800. I believe the 7800 FAQ discusses the different 7800 models and which ones R.T. is most compatible with. Unfortunately, I don't know of any easy way to tell the different Robot Tank carts apart, other than to test them.

 

The 7800 FAQ does go into more detail - http://www.atariage.com/7800/faq/index.htm...l?SystemID=7800

[Tempest]

IIRC Robot Tank uses an odd bankswitching scheme (FE?) that not all 7800's like. I believe it is the only game to use this bankswitching. The reason it works on some 7800's and not others is that Atari made minor changes to the 7800's design over time to save money. The earliest models don't seem to the trouble, while most of the later models do. If Robot Tank works on your 7800 then the Supercharger and Decathlon should work as well.

 

Tempest

[khryssun]

A modification can be done on the 7800's mainboard if robot tank doesn't work with it.

 

I don't remember where I found the schematics (maybe it's still into the Atari Age Message Board Archives) but I've done the modification 2 years ago (as I remember it's just a resistor to remove).

 

I made an avanced version of this modification with a switch button located at the back of the 7800 so I can enable/disable the resistor.

 

and it works fine.

[Thomas Jentzsch]

IIRC Robot Tank uses an odd bankswitching scheme (FE?) that not all 7800's like.  I believe it is the only game to use this bankswitching.

IIRC Decathlon and Space Shuttle where originally using this special bankswitching too, but later releases where changed to use standard Atari bankswitching.

[jsoper]

Ya know, a search in the 7800 forum for "robot tank" would have provided all the info you wanted.

http://www94.pair.com/jsoper/7800_compat.html