You posted in the NG forum so hoping that you have an NG remote.
Duplicate the device using ProntoEditNG or ProntoEditProNG (PENG or PPENG) and then plug in the codes needed.
Now, where to get the codes? Search the Classic Pronto Files Section for my Sony CD Changer CCF. You can then File->Import CCF into the editor to make a config (PCF file). Merge this file into your config and go from there. i.e. you can drag links, etc...
I'm sure that once you review this CCF, you will find that you need nothing more. It has every code for CD1, CD2, and CD3 (Command Mode 1, 2, 3) including all known discrete codes.
Then, there's also the very old Sony CD Supercharger program that when combined with SuperNudelist data files (SNL also available in the Classic Pronto files section) will allow you to generate a CCF that, via IR commands, labels artists and disc names in the changer (same as attaching a keyboard and typing the names). If using NG remote, you can File->Import CCF... to put this file into an NG remote to use.
Note that only 200 artists are supported on the Sony changers but other than that, should work just fine.
With the SuperCharger program, there is a readme.txt file that discusses the IR protocol used by Sony so if you are a techie, you might be interested in that as well as the Pronto Hex IR Format document in the Classic Pronto Files Section under User Documentation. This document is of course, by the now famous Mr. Barry Gordon.
