Games on microchip

Game cartridges are, basically, ROM microchips on a circuit board; an easy plug-in interface. Some cartridges contained more than one chip, such as POKEY games. Also, NES games usually split the game logic and graphics into separate chips on the cart (CHR ROM and PRG ROM). These are listed as cartridge media on UVL.

But some games shipped with, or only as, chips. These were meant to be plugged into the main board of the system. No cartridge port. Of course their were coin-ops that were designed with the option of chaining the game later. There were also some coin-ops that were never intended to have interchangeable games but the important chips (or all of them) were socketed and thus it was possible and therefore done to save costs; offering arcade owners a less-expensive game than a whole new cabinet and re-use of an old cabinet that was not as profitable as when it was new. But, it is not just coin-ops, home systems, especially computer systems, had socketed chips, or just open sockets, that game makers used for games sold with chips. Doctor Who And The Mines Of Terror for the BBC Micro is probably the best known example. It shipped with a disk and a ROM chip. In the case of the BBC, there were sockets on the motherboard that were actually intended to house ROM chips containing end-user applications.

So, what to call this?
Media: ROM chip.
microchip
romchip
romchips
ic
?

I recall there being some talk about cartridges on some platforms being cleverly used effectively as expansion slots besides for interfacing with the ROM, adding functionality to the main platform. Some Sonic game on Megadrive did something akin to that, I think.

Anyway, romchip seems appropriate for most cases. Integrated circuit implies, to me at least, that there's more going on.