As we know, when the Intellivision II was designed, Mattel implemented the stricter copyright routine so third-party games, namely Coleco, (and Mattel's own Word Fun) wouldn't work on the new console. It seems like everyone eventually figured out how to get around this, by many already-released games were incompatible. As far as I'm aware, Coleco never re-released their games in the US market with updated code to get around the Inty II copyright check. However, I've read that some versions of the European CBS Electronics release of Coleco's games have updated code and (in theory) should run on an Inty II. The real question is - would you want to? Coleco is somewhat notorious for intentionally gimping their Inty ports to make the ColecoVision look better.
In my case, however, Venture is one of my favorite Intellivision games after the AD&Ds! So I decided to order a CBS copy of Venture and got it working. It could just be my imagination, but the CBS version seems to run noticeably smoother than the US-market Coleco version (on the Inty I of course).
- Pictures 1 & 2 - Obtain the "Green Dragon w/ White Lines" box version of Venture. The are at least two other CBS box versions; I'm not sure if they all contain Intellivision II compatible code.
- Pictures 3 & 4 - Great! You have a Venture cartridge that has the right code to work in an Inty II. Only one problem - the cartridge doesn't fit in the console! There are three "chines" above the PCB contacts which prevent insertion into the US-market Intellivision II. Unscrew the two screws on the back of the cart.
- Picture 5 - The other half of the cart is normal and should fit in any Intellivision. No work needed here.
- Picture 6 - Break off (ouch! sorry) the three chines with some needle-nose pliers (etc) and sand/file down the remaining nubs.
- Picture 7 - Reassemble the cartridge (was it really that easy?).
- Picture 8 - Not quite! Now that you've filed down the chines, the cartridge actually goes too far into the Intellivision II. So when you insert it, insert it about 5mm short of the hard stop. Do that, and you're playing Venture on an Intellivision II!