Warning: this is an htmlized version!
The original is across this link,
and the conversion rules are here.
#!/bin/sh
# gs-640c-bw
# Edrx 2003mar12
# See:
# lynx http://hpinkjet.sourceforge.net/printmodedescr.php#commands
# lynx $usr_src/hpijs-1.0.4/hpijs_readme.html#Device
# (find-available "hpijs")
# (find-es "hardware" "hp640c")

exec gs -sDEVICE=ijs				\
	-sIjsServer=hpijs			\
	-dIjsUseOutputFD			\
	-sDeviceManufacturer=HEWLETT-PACKARD	\
	-sDeviceModel=DESKJET\ 640C		\
	-sIjsParams="Quality:ColorMode=0"	\
	$*

#    * DeskJet 600C series photo (DJ6xxPhoto | DJ6xxP) - This device
#      class supports the DESKJET 610, DESKJET 612, DESKJET 640, DESKJET
#      648, DESKJET 690, DESKJET 692, DESKJET 693, DESKJET 694, DESKJET
#      695, DESKJET 697. The following options can be selected with
#      Ghostscript commands.
#  Grayscale
#    Quality=0 ColorMode=0 MediaType=0 PenSet=2
#  Normal (default)
#    Quality=0 ColorMode=2 MediaType=0 PenSet=2
#  Photo
#    Quality=2 ColorMode=2 MediaType=1 PenSet=4