There doesn't seem to be much info around on the web about this multigame system from an English company called Century (not the same company as Centuri). The design of the board looks as if it were originally designed to be a home console system, with some form of cartridge system, because there are many effects supported by the hardware that do not seem to be used by any of the games.
The Hardware is based around the Signetics S2650 CPU and the Signetics 2636 object controller (sprites!) - One CPU is used to run the actual game code, and this can pass data to a second CPU which runs the sound code. (code for both of these are on the cartridge) . The third CPU is used to handle the LCP speech chip. which although it is used for speech, "game system operational", it is also used for sound effects in the games.
There is in existance a troubleshooting document for the hardware, since I was offered a copy long ago by someone on the net, unfortunately, the email address I have bounces so I never did get that information. If you have any information on the S2636 sprite chip, or on the CVS hardware itself, then please let me know!
The information that I have gathered so far, is now included in a DjVu file, linked here
A picture of the actual PCB. The cartridge is the item on the left with the two 60 pin cables attached. The grey chip on that, with the gold plate, is the protection device used by some of the later games, although most of the games also exist in an unencrypted state which can be used by replacing the chip with 10 links.
The sound board can be seen on the right, and comprises the S2650 and code (lower half), the other S2650, the 5100 speech chip and some ram in the upper half. Boards seem to have various numbers of volume controls as the one in the picture is fully populated, but I have boards with only 2 on.