For backward compatibility reasons it may be desirable for a 7700 (L1/L2 L1/L1 or L1 only) simulator to emulate a 4760 simulator. When a 7700 has been put into 4760 emulation (or legacy) mode it can then run with VMS Workstation software.
The unit will then operate as an STR4760 until you power cycle the unit or the command in step 1 is re-sent, replacing the 1 with a 0, i.e. TEST LEG4760 0, followed by the SDC! command.