Samsung ML-2151N-XBH - Manual (Page 210)

P ROGRAMME I NSTALLING P RINTER O PTIONS F.3
F
Installing Memory and PostScript
DIMMs
Additional printer memory and the PostScript option are
provided on DIMMs (Dual In-line Memory Modules). This
procedure is applicable to either option.
N OTE : For using the ML-2150 printer with the PostScript driver,
you need to install an optional PS DIMM.
1 Turn the printer power off and unplug all cables from the
printer.
2 Remove the two screws on the rear of the printer, then
remove the control board cover.