With the overhaul of commands, some helpers needed tweaks while
new ones were added to abstract p3io command details with a
common interface, e.g. dealing with the command length field.
Using a real DDR P3IO (Dragon PCB), the overall P3IO command
structures improved significantly. Added further notes about
unknown/unclear commands that were not derivable from the
DDR 18 game binary either.
Note that this module is also used by jubeat to some extend.
The initial design apparently assumed a greater overlap in
commands. This now seems less likely as many commands appear
to be DDR specific.
Refactoring/splitting this is a major effort that is not being
addressed here.
icex2