It's not the number of speed steps that change between a CAB-1 and a CAB-2, its the way they are "addressed". The most overlooked/least understood pages in the Legacy manual has to do with "Modes". Legacy controller supports three modes, CAB-1, TMCC, and Legacy. You can run any Legacy loco in any of these modes. You can run a TMCC equipped loco in CAB-1 or TMCC. CAB-1 mode is reserved for backwards compatibility, control of variable voltage supplies (PowerMaster, TPC) and some accessories like the Crane Car and some action accessory/cars that use variable voltage to function.
TMCC and Legacy use "absolute speed steps". CAB-1 uses relative. This is why TMCC loco's run better with the CAB-2/Legacy base than the do with the CAB-1/TMCC base. This is also why Odyssey 1 loco's behave better under CAB-2/Legacy than they do under the CAB-1/TMCC command base. Please note that this is an issue with the CAB-1 and not TMCC per se. An original TMCC command base can generate absolute speed commands but the CAB-1 can't. You need a computer program that sends commands down the serial data line to get a TMCC loco to use absolute speed steps with the original Command Base. The CAB-2 can generate all three types/sets of commands.
