I'm writing an academic text in American English. I'm not sure about the compound words:

    DB-9 connector
    end-of-packet
    16-bit registers
    Avalon-MM slave interface
    RS-232 interface
    Bidirectional full-duplex communication
    MSB (bit 7)
    transmitted LSB (​bit-0​) first
    endofpacket or end-of-packet?
    32-bit system
    provability-checking algorithm
    the model checker (or "the model-checker"?
    I / O, i/o or I/O ?
    base-case or basecase or base case?

I feel it's been difficult to know where to place the hyphen, if anywhere.