Lexmark C762 - Manual (Page 201)

PostScript
4-24
duplexmode
— duplexmode boolean
queries the current value for the Duplex page device parameter.
true printing mode is duplex
false printing mode is simplex
Note: For printers that do not support duplexing, this value is always false .
This operator is equivalent to executing the following PostScript emulation
sequence:
currentpagedevice /Duplex get
Error: stackoverflow
enginesync
— enginesync boolean
indicates if the printer waits for the last page of a job to print before returning a
Ctrl-D to the host computer.
Error: stackoverflow