450(1)                                                     450(1)



     NAME
          450 - filter text containing printer control  sequences  for
          the DASI terminal

     SYNOPSIS
          450

     DESCRIPTION
          450 supports special functions of, and optimizes the use of,
          the DASI 450 terminal, or any terminal that is functionally
          identical, such as the DIABLO 1620 or XEROX 1700.  It con-
          verts half-line forward, half-line reverse, and full-line
          reverse motions to the correct vertical motions.  It also
          attempts to draw Greek letters and other special symbols in
          the same manner as 300(1).  450 can be used to print equa-
          tions neatly, in the sequence:

             neqn file ... | nroff | 450


     WARNINGS
          Make sure that the PLOT switch on your terminal is ON before
          450 is used.  The SPACING switch should be put in the
          desired position (either 10- or 12-pitch).  In either case,
          vertical spacing is 6 lines/inch, unless dynamically changed
          to 8 lines per inch by an appropriate escape sequence.

          450 can be used 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 hitting the RETURN key
          in these cases, you must use the line-feed key to get any
          response.

          In many (but not all) cases, the use of 450 can be eliminat-
          ed in favor of one of the following:

             nroff -T450 files ...

          or

             nroff -T450 -12 files ...

          The use of 450 can thus often be avoided unless special de-
          lays or options are required; in a few cases, however, the
          additional movement optimization of 450 may produce better-
          aligned output.

          The neqn names of, and resulting output for, the Greek and
          special characters supported by 450 are shown in greek(5).






     April, 1990                                                     1

     450(1)                                                     450(1)



     FILES
          /usr/bin/450

     SEE ALSO
          300(1), eqn(1), mesg(1), nroff(1), stty(1), tabs(1), tbl(1),
          tplot(1G), greek(5).

     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.







































     2                                                     April, 1990