Here ya go...from
http://wagnerone.com/enteract/dat/tascam/1. How do I disable SCMS?
* If applicable, eject tape and close door.
* Power off the unit.
* With unit off, depress & hold the "Execute" button and power unit on.
* The display will read "SC-OFF" indicating that SCMS is set at 00.
* The DA20 will remain in this mode until this procedure is repeated to set it back to SCMS xx. It will not return to SCMS xx by simple cycling the power.