No longer in GT.M since: V5.3-003
MTRDONLY, Cannot write to a READONLY magtape
Run Time Error: This indicates that a WRITE command attempted to access a read-only tape.
Action: Verify that the proper tape is mounted. If the tape is to be written, insert the write ring and remount. If the tape is properly mounted, ensure that the tape was OPENed NOREADONLY.
