Brother HL-1240 - Manual (Page 51)

CHAPTER 2 OPTIONS
2-9
1.
Make sure that the power switch is turned off.
!
Caution
Be sure to turn off the power switch before connecting or disconnecting the
interface cables, or the printer may be damaged.
2.
Insert and secure the parallel interface connector from the computer into the parallel
interface port of the printer.
3.
Insert and secure the serial interface connector from the computer or Macintosh into
the serial interface port of the printer.
4.
Turn on the power switch.