The line printer is found in the Instrument Computer room, beside the PE 3210 System Console. There is a black box with a switch, most likely resting on the floor beside the printer. Ensure that this selector switch is switched to Telescope Computer, i.e. not to Instrument Computer. (It is intended to replace it by a device without switch.) Go back to the control room and type at the UI console:
L(IST)/PRI(NTER)
Wait for a few seconds. If nothing happens, type (on the PE 3220 Telescope System Console):
*D(isplay) M(emory)
in order to check that the Spooler task, `.SPL', is not Paused.
(See section 
for more details about the Perkin Elmer
operating system.) If the Spooler task is paused, type on System Console:
*T(ask) .SPL
*CO(ntinue)
and try again LI/PRI at the User Interface. If .SPL was not loaded, then type on System Console:
*STARTSPL
and try LI/PRI again.