lj4_font(5) — Linux manual page

Name | Description | Limitations | Files | See Also | COLOPHON

lj4_font(5)                  File Formats Manual                 lj4_font(5)

Name         top

       lj4_font - groff fonts for use with devlj4

Description         top

       Nominally, all Hewlett-Packard LaserJet 4-series and newer printers
       have the same internal fonts: 45 scalable fonts and one bitmapped
       Lineprinter font.  The scalable fonts are available in sizes between
       0.25 points and 999.75 points, in 0.25-point increments; the
       Lineprinter font is available only in 8.5-point size.

       The LaserJet font files included with groff assume that all printers
       since the LaserJet 4 are identical.  There are some differences
       between fonts in the earlier and more recent printers, however.  The
       LaserJet 4 printer used Agfa Intellifont technology for 35 of the
       internal scalable fonts; the remaining 10 scalable fonts were
       TrueType.  Beginning with the LaserJet 4000-series printers
       introduced in 1997, all scalable internal fonts have been TrueType.
       The number of printable glyphs differs slightly between Intellifont
       and TrueType fonts (generally, the TrueType fonts include more
       glyphs), and there are some minor differences in glyph metrics.
       Differences among printer models are described in the PCL 5
       Comparison Guide and the PCL 5 Comparison Guide Addendum (for
       printers introduced since approximately 2001).

       LaserJet printers reference a glyph by a combination of a 256-glyph
       symbol set and an index within that symbol set.  Many glyphs appear
       in more than one symbol set; all combinations of symbol set and index
       that reference the same glyph are equivalent.  For each glyph,
       hpftodit(1) searches a list of symbol sets, and selects the first set
       that contains the glyph.  The printing code generated by hpftodit is
       an integer that encodes a numerical value for the symbol set in the
       high byte(s), and the index in the low byte.  See groff_font(5) for a
       complete description of the font file format; symbol sets are
       described in greater detail in the PCL 5 Printer Language Technical
       Reference Manual.

       Two of the scalable fonts, Symbol and Wingdings, are bound to
       256-glyph symbol sets; the remaining scalable fonts, as well as the
       Lineprinter font, support numerous symbol sets, sufficient to enable
       printing of more than 600 glyphs.

       The metrics generated by hpftodit assume that the DESC file contains
       values of 1200 for res and 6350 for unitwidth, or any combination
       (e.g., 2400 and 3175) for which res × unitwidth = 7620000.  Although
       HP PCL 5 LaserJet printers support an internal resolution of 7200
       units per inch, they use a 16-bit signed integer for cursor
       positioning; if devlj4 is to support U.S. ledger paper
       (11 in × 17 in; in = inch), the maximum usable resolution is
       32767 ÷ 17, or 1927 units per inch, which rounds down to 1200 units
       per inch.  If the largest required paper size is less (e.g.,
       8.5 in × 11 in, or A5), a greater res (and lesser unitwidth) can be

Limitations         top

       Font metrics for Intellifont fonts were provided by Tagged Font
       Metric (TFM) files originally developed by Agfa/Compugraphic.  The
       TFM files provided for these fonts supported 600+ glyphs and
       contained extensive lists of kerning pairs.

       To accommodate developers who had become accustomed to TFM files, HP
       also provided TFM files for the 10 TrueType fonts included in the
       LaserJet 4.  The TFM files for TrueType fonts generally included less
       information than the Intellifont TFMs, supporting fewer glyphs, and
       in most cases, providing no kerning information.  By the time the
       LaserJet 4000 printer was introduced, most developers had migrated to
       other means of obtaining font metrics, and support for new TFM files
       was very limited.  The TFM files provided for the TrueType fonts in
       the LaserJet 4000 support only the Latin 2 (ISO 8859-2) symbol set,
       and include no kerning information; consequently, they are of little
       value for any but the most rudimentary documents.

       Because the Intellifont TFM files contain considerably more
       information, they generally are preferable to the TrueType TFM files
       even for use with the TrueType fonts in the newer printers.  The
       metrics for the TrueType fonts are very close, though not identical,
       to those for the earlier Intellifont fonts of the same names.
       Although most output using the Intellifont metrics with the newer
       printers is quite acceptable, a few glyphs may fail to print as
       expected.  The differences in glyph metrics may be particularly
       noticeable with composite parentheses, brackets, and braces used by
       eqn(1).  A script, located in /usr/local/share/groff/1.22.4/font/
       devlj4/generate, can be used to adjust the metrics for these glyphs
       in the special font “S” for use with printers that have all TrueType

       At the time HP last supported TFM files, only version 1.0 of the
       Unicode standard was available.  Consequently, many glyphs lacking
       assigned code points were assigned by HP to the Private Use Area
       (PUA).  Later versions of the Unicode standard included code points
       outside the PUA for many of these glyphs.  The HP-supplied TrueType
       TFM files use the PUA assignments; TFM files generated from more
       recent TrueType font files require the later Unicode values to access
       the same glyphs.  Consequently, two different mapping files may be
       required: one for the HP-supplied TFM files, and one for more recent
       TFM files.

Files         top

              device description file

              font description file for font F

              corrects Intellifont-based height metrics for several glyphs
              in the special font for TrueType CG Times (LaserJet 4000 and

See Also         top

       groff(1), hpftodit(1), grolj4(1), groff_font(5)

COLOPHON         top

       This page is part of the groff (GNU troff) project.  Information
       about the project can be found at 
       ⟨http://www.gnu.org/software/groff/⟩.  If you have a bug report for
       this manual page, see ⟨http://www.gnu.org/software/groff/⟩.  This
       page was obtained from the project's upstream Git repository
       ⟨https://git.savannah.gnu.org/git/groff.git⟩ on 2020-07-14.  (At that
       time, the date of the most recent commit that was found in the repos‐
       itory was 2020-07-12.)  If you discover any rendering problems in
       this HTML version of the page, or you believe there is a better or
       more up-to-date source for the page, or you have corrections or
       improvements to the information in this COLOPHON (which is not part
       of the original manual page), send a mail to man-pages@man7.org

groff            16 May 2020                     lj4_font(5)

Pages that refer to this page: groff(1)grolj4(1)hpftodit(1)