I’ve found the best way to program a DCC decoder, and it’s free (depending upon your DCC system)!
DecoderPro is a free application that runs on pretty much any WindowsXP, Windows7, MacOS or Linux computer (OS list updated 12/31/12 to include Windows7 and delete Windows98). If you have an NCE Powerhouse Pro system of just about any vintage, you can simply plug your computer into the serial port and you’re ready to program just about any decoder currently on the market. Other systems will require some sort of computer interface (for Digitrax users, that’s the MS100).
Decoder settings, including those pesky custom speed curve tables, can be easily adjusted and sent to the loco, along with literally every other setting in the decoder, and all through easy to read and understand screens.
Once you’ve got all your settings for a particular loco set, you can save it off for future reference, or, if you’ve got a “fleet” of one particular loco type, simply change the address and download all the same parameters to each loco.
Did I mention this is free software? What more could you ask for?