
Read_Me file for Hewlett-Packard printers.
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The HP.LasJet-II printer definition file is for use with the HP LaserJet II
printers. The HP.LasJet-III file is for use with HP LaserJet series III
printers and similar compatibles eg. Star LaserPrinter 4, Star LaserPrinter
8III, HP LaserJet IIP. The HP.DeskJet file is for use with HP DeskJet
printers and similar compatibles. The HP.DeskJet+ file is for use with HP
DeskJet Plus printers and similar compatibles eg. Olivetti JP 150 and JP
350, HP DeskJet Professional, HP DeskJet 500 etc. The difference between the
four files is minor: the LasJet-II file has the multiple copies command
enabled, the DeskJet+ file has the compression facility enabled,  the
LasJet-III file has both multiple copies and compression enabled, and the
DeskJet file has neither of these enabled. You should make your choice of
which file to use on which of these two facilities your printer supports. In
all other respects the four files are functionally identical. This does not
however mean that the results will be the same on all printers.

For graphics the results should be the same, except that printing will be
faster if compression is in use. For text printing there could be
significant variation in the results. It all depends on what font heights,
pitches and styles your printer supports. The full range of heights and
pitches are specified in the definition files for both Portrait and
Landscape mode to obtain all the features of fancy text printing. If however
your printer does not have the requested font style, then the printer will
select the best approximation it has. Thus for example expanded text
(6 characters per inch) does not come out as expanded on the LaserJet II,
because the widest text the LaserJet II has is 10 characters per inch.
Installing a Courier font card may improve the situation, if it has some of
the sizes requested on it. 6, 10, 12 and 17 CPI are the pitches used, and
12 and 8.4 point (for superscript and subscript) are the heights used in
Portrait mode. In Landscape mode the corresponding pitches are 8.5, 14, 17
and 24 CPI and the heights used are 8.5 and 6 point. Italic style is missing
from some printers, the Olivetti JP 150 and JP 350 do not do underlining in
Landscape mode, and no printer seems to support the Light print weight.
Sometimes text will come out in a Typeface other than Courier eg. Landscape
text on the LaserJet II comes out in the Line Printer typeface. This is
because the Typeface is last on the list of priorities for the best match
algorithm - it deems getting the size right more important.

Most of the ISO Latin 1 international characters are obtained by telling the
printer to change to the ISO Latin 1 (ECMA-94) symbol set. The few
characters that cannot be obtained in this manner (characters 128 to 159)
have mappings defined for them. Character 160 (non-breaking space) is mapped
to a standard space as some printers (eg. Star LaserPrinter 8III) consider
character 160 to be invalid.

Not all of the control sequences are held in the printer definition file
for LaserJet printers, for technical reasons. For text printing, most of
the control sequences are in the file. The control sequences for manual
feed, auto feed and paper tray size selection are in
!Printers.lj.Resources.Messages. The control sequences used for position
changing, setting the lines per page at the start of each new line or new
page and for performing tabs are in the !Printers.lj.Resources.Support BASIC
program file. Also page titles (if enabled) are printed using the secondary
font. You should not need to modify the control sequences in the Support
BASIC program, as they are very standard. It is unlikely that you will need
to modify the control sequences in the Messages file.

For graphics printing, all of the control sequences are held in the 
PDumperLJ module. Although this is rather inflexible as you cannot change
these sequences it is unavoidable and you are very unlikely to need to
change them. You can control whether or not the multiple copies command is
supported and whether or not compression is supported with !PrintEdit, and
that is all.

If you have a LaserJet II, IID or IIID with a PostScript card fitted, you
should be able to use the PostScript printer definitions LJ_II_PS, LJ_IID_PS
and LJ_IIID_PS as appropriate.
