User`s guide

SET DXx
(DX)
Sets the specified unit of the DX diskette handler (RX01 diskettes).
Format
SET DXx condition
Condition
[NO]WRITE
WRITE, the default, write enables DX unit x. NOWRITE write locks DX unit x.
NOWRITE affects both the memory copy and the disk file of the handler.
RT–11 Command Descriptions 231