On February 1, 2008 at 19:09, markrubin said...
need serial commands, or IR codes for Onkyo T-4555 HD tuner platform
nice unit: am/fm/HD Radio/RDS/Sirius/XM (Sirius/XM rcvrs req) with RS232 port
Don't know if you still are in need of this but I just sent you an email with the RS-232 protocol & command sheet.
I also sent the file to Remote Central but I don't know how long they take to be published on this site.