Fig. 1: OpenCart64

Open16Cart is an Open Hardware Cartridge for the Commodore 16 line of computers. It supports 16 or 32 KB ROM images using 27xxx style (E)EPROM(s).

C16 ROMs are normally 16 or 32 Kb (see list below). OpenC16Cart supports both, 8 KB might or might not work, I'm not aware of any carts of this size.

For the 16 KB configuration, only use the LO ROM. If you are using 64 KB (E)EPROMS, you can store up to 4 images, which you can select using the A14 and A15 jumpers above the LO ROM:

Image # A14 A15
1 L L
2 H L
3 L H
4 H H

For the 32 KB configuration, use both the LO and HI ROMs. 32 Kb ROM are usually distributed as two 16 Kb chunks, and one goes on each ROM, in corresponding positions. In this case you will also be able to switch among 4 different images, by moving the A14/A15 jumpers on BOTH ROMs.

The cartridge also has some more jumpers, named J1-J6, which are there because the cart that was used to design this PCB had them, but I don't really know whether they have any useful purpose:

  • J1 and J4 MUST be placed horizontally. The normal position is the middle one. The other positions will probably be useful with 8K ROMs, but since this configuration has not been tested, you should never use them.
  • J2, J3, J5 and J6 go vertically. The normal position is the upper one.