300(1)                               SysV                               300(1)



NAME
     300, 300s - handle special functions of DASI 300 and 300s terminals

SYNOPSIS
     300 [ +12 ] [ -n ] [ -dt,l,c ]

     300s [ +12 ] [ -n ] [ -dt,l,c ]

DESCRIPTION
     The 300 command supports special functions and optimizes the use of the
     DASI 300 (GSI 300 or DTC 300) terminal; 300s performs the same functions
     for the DASI 300s (GSI 300s or DTC 300s) terminal.  It converts half-line
     forward, half-line reverse, and full-line reverse motions to the correct
     vertical motions.  In the following discussion of the 300 command, it
     should be noted that unless your system contains the DOCUMENTER'S
     WORKBENCH Software, references to certain commands (e.g., nroff, neqn,
     eqn,) will not work.  It also attempts to draw Greek letters and other
     special symbols.  It permits convenient use of 12-pitch text.  It reduces
     printing time 5 to 70%.  You can use the 300 command to print equations
     neatly, in the sequence:

          neqn file ... | nroff | 300

OPTIONS
     +12       Permits use of 12-pitch, 6 lines/inch text.  DASI 300 terminals
               normally allow only two combinations: 10-pitch, 6 lines/inch,
               or 12-pitch, 8 lines/inch.  To obtain the 12-pitch, 6 lines per
               inch combination, turn the PITCH switch to 12, and use the +12
               option.

     -n        Controls the size of half-line spacing.  A half-line is, by
               default, equal to 4 vertical plot increments.  Because each
               increment equals 1/48 of an inch, a 10-pitch line-feed requires
               8 increments, while a 12-pitch line-feed needs only 6.  The
               first digit of n overrides the default value, thus allowing for
               individual taste in the appearance of subscripts and
               superscripts.  For example, nroff half-lines can be made to act
               as quarter-lines by using -2.  You can also obtain appropriate
               half-lines for 12-pitch, 8 lines/inch mode by using the option
               -3 alone, having set the PITCH switch to 12-pitch.

     -dt,l,c   controls delay factors.  The default setting is -d3,90,30.
               DASI 300 terminals sometimes produce peculiar output when faced
               with very long lines, too many tab characters, or long strings
               of blankless, non-identical characters.  One null (delay)
               character is inserted in a line for every set of t tabs, and
               for every contiguous string of c non-blank, non-tab characters.
               If a line is longer than l bytes, 1+(total length)/20 nulls are
               inserted at the end of that line.  Items can be omitted from
               the end of the list, implying use of the default values.  Also,
               a value of zero for t (c) results in two null bytes per tab
               (character).  The former may be needed for C programs, the
               latter for files like /etc/passwd.  Because terminal behavior
               varies according to the specific characters printed and the
               load on a system, you may have to experiment with these values
               to get correct output.  The -d option exists only as a last
               resort for those few cases that do not otherwise print
               properly.  For example, you can print the file /etc/passwd
               using -d3,30,5.  The value -d0,1 is a good one to use for C
               programs that have many levels of indentation.

     You can use 300 with the nroff -s flag or .rd requests, when it is
     necessary to insert paper manually or change fonts in the middle of a
     document.  Instead of pressing RETURN in these cases, you must use the
     line-feed key to get any response.

     In many (but not all) cases, the following sequences are equivalent:

          nroff -T300 files ...   and   nroff files ... | 300
          nroff -T300-12 files ...   and   nroff files ... | 300 +12

     Using 300 can often be avoided unless special delays or options are
     required; in a few cases, however, the additional movement optimization
     of 300 can produce better-aligned output.

     The neqn names of, and resulting output for, the Greek and special
     characters supported by 300 are shown in greek(5).

NOTE
     The delay control interacts heavily with the prevailing carriage return
     and line-feed delays.  The stty(1) modes nl0 cr2 or nl0 cr3 are
     recommended for most uses.

WARNING
     If your terminal has a PLOT switch, make sure it is turned ON before 300
     is used.

BUGS
     Some special characters cannot be correctly printed in column 1 because
     the print head cannot be moved to the left from there.
     If your output contains Greek and/or reverse line-feeds, use a friction-
     feed platen instead of a forms tractor; although good enough for drafts,
     the latter has a tendency to slip when reversing direction, distorting
     Greek characters and misaligning the first line of text after one or more
     reverse line-feeds.

SEE ALSO
     450(1), mesg(1), graph(1G), stty(1), tabs(1), tplot(1G).
     eqn(1), nroff(1), tbl(1) in the UNIX System V Documenter's Workbench
     Reference Manual
     greek(5) in the SysV Programmer's Reference.