I got this info from the ColecoVision FAQ
30-pin female 0.1"-spaced dual-sided card edge connector at the console.
Wondering why there are pins for A13 and A14 when the enables are for 8K chunks? Seems Coleco was nice enough to put all 32K of game ROM in a flat address space. While production carts have up to four 8k ROMs, each with its own enable line, the A13 and A14 lines are handy for slapping in a 27256 EPROM without worrying about building a logic circuit to convert the four enable lines into two additional addresses. All you have to do is AND the four enables together to make the EPROM's single enable. Capiche?