Ah, I understand.
You can play both games than like on that Berzerk/Frency-modul from Jrok?
Btw, Andre, I sent you a PM some days ago ![Wink ;)](http://www.dragonslairfans.com/smfor/Smileys/default/wink.gif)
No, you're completely mixing up stuff.
Imagine it is 1983. You are an operator and your Galaxian machine is not making the money like it used to do. Now you could buy a new cab, but that is pretty damn expensive. Then you look in a arcade operators magazine and you see an add for an upgrade kit that converts Galaxian to another game.
That is a cheap way to get a "new" machine and earn more on the same cab that you already have....
This is such a kit. These kit came in various "builds" ranging from simple EPROM swaps (remove old EPROMS, put in new one's) to extra PCB's like this (In this case put in a nice case).
You could not select games or even play the old game, it was a "one way" conversion, there was no need to play the old game, that was boring and done at that time
![Wink ;)](http://www.dragonslairfans.com/smfor/Smileys/default/wink.gif)
The Jrok boards are of course of very recent date and are complete replacements of an entire board-set.
All the original electronics of such a board-set (7 boards with Berzerk/Frenzy !) are "compressed" into a Jrok board.
You do not attach it to an existing board like the kits mentioned above.