Addressing mode lines:

A:<mode>:<mode spec>:<pattern>:<byte specs>

<mode>

is a unique label for this addressing mode

<mode spec>

specifies the number of argument bytes that will be needed followed by "r" if this mode uses relative addressing

<pattern>

this is either a perl regular expression to match an argument, or a ! seperated list of other addressing modes (this allows one addressing mode to have different patterns with different ways of calculating the bytes).

<byte spec>

a colon seperated list of expressions used to calculate the argument bytes

Op code lines:

O:<op code>:<mnemonic>:<addressing mode>