DCSRC=DCS Remote Commander. You were close
It is the most basic form of DCS control, allowing you to use an infrared remote to access a few more bells and whistles, so to speak, than conventional transformer operation. It only works with locos that have not been previously given an ID number by a regular DCS system (which would describe any loco in a MTH ready-to-run set unless someone goofed in testing)TMCC=TrainMaster Command Control. It's Lionel's first command system. It's been superseded by Legacy, which performs more tricks. Legacy can run TMCC locos (since it's an extended version of TMCC), but TMCC locos don't get any additional capabilities under Legacy (other than possibly smoother operation). In a similar vein, a TMCC remote will run Legacy locos, but not be able to access their advanced functions.
Neither of the above will operate DCS locos in command, but you can run them conventionally with an add-on called a TPC (track power controller) which is essentially a remote-controlled transformer handle for conventional trains.
A DCS system won't run TMCC/Legacy locos by itself, but you can connect the Lionel boxes to the DCS box (with an MTH-provided cable) and issue TMCC-level control signals through it (the Legacy-specific control codes are proprietary to Lionel). Or, you can run the TMC/Legacy units conventionally--the DCS control box includes TPC-like functionality.
The two systems will co-exist on the same track--I once ran a double-headed train pulled by both a TMCC and a DCS loco, using one DCS controller. It was a juggling act to be sure, and there was no quick way to stop if something went wrong, but the stunt worked. If you can find a TMCC command base or can afford a Legacy system, this would be a good way to remain compatible with all the industry's offerings.
---PCJ
