Note: An optional card is either a font card, firmware card, or flash
CAUTION—SHOCK HAZARD: To avoid the risk of electrical shock,
if you are accessing the controller board or installing optional hardware
or memory devices sometime after setting up the printer, then turn
the printer off, and unplug the power cord from the electrical outlet
before continuing. If you have any other devices attached to the printer,
then turn them off as well, and unplug any cables going into the printer.