The standard (`occidental') and Japanese (`oriental) Hershey glyphs were
digitized by Dr. Allen V. Hershey at what is now the U.S. Naval Surface
Weapons Center in Dahlgren, VA (formerly the U.S. Naval Weapons
Laboratory), c. 1967.  There have been at least five publicly released
versions of the Hershey glyphs.

#-1. The versions distributed by Dr. Hershey himself, in the late 1960's
and 1970's.  These were distributions of his typographic software, of which
the glyph distribution was a part.  Initial distributions were on punched
cards, and later ones were on magnetic tape.  At least 120 copies of the
typographic software were distributed.  It is not known how many distinct
releases there were, either of the software or of the glyphs.

#0. The NBS [U.S. National Bureau of Standards] publication "A Contribution
to Computer Typesetting Techniques", dated 1976, and the accompanying
magnetic tape.  This presumably included all glyphs in use at that time.
In Figure 15, 45 additional glyphs (digitized by Norman Wolcott at NBS)
were shown, but the data for them were not given.  (Glyphs 2250, 2260 were
probably included in Figure 15 erroneously; they were also listed among the
standard glyphs).

#1. The Usenet distribution of Pete Holzmann and Jim Hurt (to the newsgroup
mod.sources, now defunct).  Circa 1985, but based on the above 1976 tape.
It introduced the scheme for encoding vector glyphs as strings which is now
used in GNU libplot.  Almost identical to the above (none of the 43 new
Wolcott glyphs), but included three additional glyphs: 997, 998, 999,
respectively "MWMXWX", "JZJZZZ", and "JZJ]Z]".  These were merely
horizontal strokes.

#2. The glyph database incorporated in the PGPLOT utility of Tim Pearson
<tjp@astro.caltech.edu>, still available by ftp and http from
astro.caltech.edu.  This was probably based, c. 1980, on a distribution
obtained either from Nelson Beebe (see #3 below) or directly from
Dr. Hershey.  It included data for the 43 new Wolcott glyphs, and 10
additional glyphs numbered 236 (an cartographic-sized `@'), 590 (an
underscore), 2078 (Aring), 3330, 3331, 3332, 3430, 3431, 3432
(umlaut-accented German letters), and 4000 (a boxed inverted questionmark).
The last of these (#4000) apparently did not originate with Dr. Hershey,
but the others did.  The horizontal stroke glyphs 997, 998, 999 from
distribution #1 were not present.  Ten glyphs were revised: 1225, 1226,
1407, 1408, 2225, 2226, 2407, 2408, 3010, and 3159.  The first eight of
these were braces.  There were 1642 separately indexed glyphs in all.

#3.  The glyph database incorporated in the PLOT79 utility of Nelson Beebe
<beebe@math.utah.edu>.  Also dates back to c. 1980; based on a tape from
Dr. Hershey himself, with local additions.  All the 1642 glyphs from #2 are
present, except that 590 (an underscore) and 2078 (Aring) are missing.
(The Hershey tape may have been a slightly earlier one than the tape used
for #2?)  Also, 911--922 (twelve outline and filled arrows) and 923--926
(four large pointing hands) were added by Dr. Beebe.  As well, 256 small
fixed-width glyphs (marker symbols taken from a plotter in the 1970's, and
low-resolution alphabets based on the plotter alphabet) in the 1500--1627
and 1700--1827 ranges were added.  There were 1912 separately indexed
glyphs in all.


In Dr. Hershey's 1995 TR, "Cartography and Typography with True Basic", he
mentions that as of 1995, his occidental repertory included 1642
characters, which is the same as the number of glyphs included in #2.  If
#4000 was not `authentic Hershey', he must have created an additional glyph
to make the total equal to 1642.  This may have been a variant lower-case
omega (such a glyph appears in several equations in his 1979 TR
"Terrestrial and Celestial Cartography").

The glyph array built into GNU libplot (see libs/common/her_glyphs.c)
includes 1641 Hershey glyphs (all the glyphs from distribution #2, with the
exception of the non-Hershey #4000).  Nelson Beebe's large pointing hands
(923--926 in distribution #3) have been included, but have been moved to
the non-Hershey section of the array (they are now numbered 4040--4043).
There are also non-Hershey glyphs from other sources.  (E.g., Robert
Beach's UGS [Unified Graphics System], which was developed at SLAC [the
Stanford Linear Accelerator Center] in the 1970's.  Its source code may
still be available at ftp://ftp.slac.stanford.edu/software/ugs77/ .)
