Yes: for the Power Cab, you need the USB interface. I have that for the Power Cab I use on the programming track, but most of my programming using JMRI software actually goes through my full Power Pro system, which has a rather old fashioned serial (RS232) interface, which uses a straight serial cable from the Power Pro box into the serial port on my train room computer. The class 24s use Zimo decoders, but for those I own with ESU LokSound decoders, I also have a LokProgrammer hooked up to the programming track, and linked through a USB cable to the computer. Each connection to my programming track is set through a 6-way rotary switch with two neutral (isolated) positions, so only one system is connected to the track at any one time. The right-hand 'Off' position in the photo is now labelled for 12V DC. While not recommended for a daily use computer, I have kept this old computer on Windows XP for reliable operation with the NCE/JMRI systems. It has access to the home network and Internet but is not normally connected unless I need updates - Windows XP is not very secure by current standards. If I download sound files or other software, I normally do that through other, more secure computers and copy the files across to the train room computer afterwards. If you have an old computer (desktop or laptop) in your household that is a bit past its "use by" date, grab it for use as a supplement for your train rooms! Sorry I have diverted the SLW thread a little off-topic.