I have used the MX-500 for a few years and absolutely love it, and I plan to purchase the MX-850 for the computer interface and rf features. My only issue is with macros and the lack of discrete on/off for the Samsung SIR-T165 OTA HDTV receiver. I also couln't find discrete on/off codes for my DVD (Zenith DVB318) , but learned here that the play and play&off combination provide a work around. Can anyone suggest a work around for the SIR-T165. This is the only thing that keeps me from the ideal remote control setup. Any input would be greatly appreciated.