Edwin, I am doing a workshop on using the 790c in Cookeville, TN this Saturday. Having reviewed the instructions for that organ recently, I believe you simply hold in the M1 piston and, after a wait, the display will show LOCKED. Turn the Alpha Dial to change it to unlocked. May I suggest the Instant Organist pistons? The three LDS churches in the Nashville area I trained last month seemed to find them very useful for the LDS services. The Instant Organist may be downloaded for free from the Frog Music Press web site home page under SUPPORT -- noel jones, aago athens, tennessee, usa 423 887-7594 ------------------------------- frog music press, publishing MIDI music moderator, rodgers organ users group at www.frogmusic.com ! ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Find new MIDI music and Guides to Rodgers Organs at www.frogmusic.com To post send messages to: rodgersorgan@xxxxxxxxxxxxx To unsubscribe or change mail delivery (digest, vacation) go to www.frogmusic.com/rodgersmem.html