1 DEFAULT
          [GTVDEF\]DEFAULT

     DEFAULT resets the parameters of the local table to their default
values.

     The  primary  and  secondary  terminal  names  and  the  terminal
protocol  (NAME1, NAME2 and PROTOCOL) are set to an "undefined" state.
DEFOUT is set to "TT".

     Escape  sequences  are  disabled  (count  -1),  and  most   other
parameters  are  set  to  zero.   Echoing during the Tektro GIN cursor
sequence (CURS_ECHO)is disabled.
1 DELETE
          [GTVDEF\]DELETE name1 [name2]

     Deletes a terminal definition  in  the  current  Binary  Terminal
Definition File (see USE).

     Arguments specify the primary terminal name  and  optionally  the
secondary  name.  These names can be abbreviated as far as they remain
non ambiguous.
1 DIRECTORY
          [GTVDEF\]DIRECTORY [Output_File]

     DIRECTORY lists the names of the terminal  definitions  available
in the current Binary Terminal Definition File (see USE).

     The output list is directed to SYS$OUTPUT:  by default, or to the
file in argument if specified.
1 FORMAT
          [GTVDEF\]FORMAT [format]

     FORMAT selects a format to specify and list the character strings
that  define  the  escape  sequences.   Available formats are DECIMAL,
HEXADECIMAL and ASCII.

     1.  Decimal format is in the form "<d1><d2>..." where d1,  d2,...
         are decimal unsigned byte values enclosed in brackets

     2.  Hexadecimal format is in the  form  "<h1><h2>..."  where  h1,
         h2,...   are  hexadecimal  unsigned  byte  values enclosed in
         brackets

     3.  Ascii format is in the form "c1c2..." where c1,  c2,...   are
         either ordinary ascii characters (SIC separators and brackets
         excluded)  or  decimal  unsigned  byte  values  enclosed   in
         brackets  (as  for  decimal  format)  or  usual mnemonics for
         control characters enclosed in brackets (such as <ESC>, <US>,
         etc...)


     To list or modify the format, just enter FORMAT with no argument.
The  current  format is returned with an error condition, and the line
keypad editing mode of SIC is triggered.

     Escape  sequences  are  always  preceded  by  a   decimal   count
corresponding  to  the number of bytes of the string.  A count -1 or 0
suppresses the escape sequence.  By convention, a count  value  of  -1
generally  means  that the corresponding action is not available (e.g.
ALPHA, GRAPHIC if no alpha plane is available, CURS1 if no  cursor  is
available,  etc...),  and  0  means  that  the corresponding action is
available but is managed internally for the current protocol.

     To list or modify an escape sequence, just enter  the  associated
command  with  no  argument.  The current sequence is returned with an
error condition, and the line keypad editing mode of SIC is triggered.
1 Language
                    GTVDEF Language Summary

USE             : Selects/creates a Binary Terminal Definition File 
DIRECTORY       : Directory of terminal definitions in the current file
DEFAULT         : Resets parameters to default values
NAME1           : Primary terminal name 
NAME2           : Secondary terminal name
READ            : Reads terminal parameters from current binary file
WRITE           : Writes terminal parameters to current binary file
LIST            : Lists terminal parameters (local or binary file) 
RENAME          : Renames a terminal definition in the current file
DELETE          : Deletes a terminal definition
2 NEWS

     1.  Preliminary version in use since 7-August-1986

     2.  Special features :  TEST command not yet  fully  debugged,  consult
         HELP TEST ; WAIT_ERASE is an integer ; specify a negative value for
         RXY to disable the packing of Tektro bytes ; 12 bit adresses in the
         Tektro GIN cursor sequence are not supported ...

     3.  In project :  more TEST facilities, selection  of  default  plotter
         configurations and procedures, HP-GL and GKS protocols, ...

1 LIST
          [GTVDEF\]LIST [name1 [name2]] [/OUTPUT File]

     Lists terminal parameters.

     The option /OUTPUT allows to redirect the output to  a  specified
file  (default  is SYS$OUTPUT).  An output file can be used later as a
command procedure for GTVDEF.  For clarity, default parameters  values
are not listed.

     Three modes of operation are selected by  the  arguments  of  the
command.

     1.  With no argument, lists the local parameters.

     2.  If a primary terminal name (and optionally a secondary  name)
         are  specified,  lists  the  associated  definitions  in  the
         current Binary Terminal Definition  File  (see  USE).   These
         names can be abbreviated as far as they remain non ambiguous.

     3.  If the argument is a star (*), lists ALL definitions  in  the
         current  BTDF  (Binary  Terminal Definition File) file.  This
         feature is designed to facilitate the migration  of  existing
         terminal   definitions   to  a  new  version  of  the  GTVIRT
         environment.

1 NAME1
          [GTVDEF\]NAME1 [name1]

     NAME1 sets the primary terminal name.  A secondary terminal  name
can be also defined to discriminate between several modes of operation
for the same terminal (see NAME2).

     Primary and secondary terminal  names  are  used  by  the  GTVIRT
library  and  by  the  associated  softwares  to  retrieve  a terminal
definition in the Binary Terminal Definition  File  (see  USE).   They
appear  for  instance  as argument of the command DEVICE to select the
current terminal in LAS, GreG and Gildas.

     To modify a name, just enter the command with no  argument.   The
current  name is returned with an error condition, and the line keypad
editing mode of SIC is triggered.
1 NAME2
          [GTVDEF\]NAME2 [name2]

     NAME2 sets the secondary terminal  name.   A  secondary  terminal
name  may  be  specified  to  discriminate  between  several  modes of
operation for the same terminal (see NAME1).

     To modify a name, just enter the command with no  argument.   The
current  name is returned with an error condition, and the line keypad
editing mode of SIC is triggered.
1 READ
          [GTVDEF\]READ name1 [name2]

     READ reads terminal parameters from the currently selected Binary
Terminal  Definition  File (see USE) into the local parameter table in
core memory.

     The terminal is identified by its primary name and optionally  by
its  secondary  name  as specified in argument(s).  These names can be
abbreviated as far as they remain non ambiguous.
1 RENAME
          [GTVDEF\]RENAME old1 [old2] /AS new1 [new2]

     Renames a terminal definition  in  the  current  Binary  Terminal
Definition File (see USE).

     Arguments of the command refer to the old primary  and  secondary
names.  Arguments of the option /AS refer to the new names.

     Old names can be abbreviated as far as they remain non ambiguous.
New names are checked against any ambiguity with other terminal names.
1 USE
          [GTVDEF\]USE [File [/CREATE]]

     USE selects a Binary Terminal Definition File (BTDF) to  be  used
in  connection  with commands DIRECTORY, READ, WRITE, LIST, RENAME and
DELETE.  The option /CREATE creates an empty BTDF file.  Remember that
the  GTVDEF  library  accesses the BDTF file pointed to by the logical
name GAG$TERMDEF.

     USE with no arguments lists the name of the current BDTF file.

     The  GTVDEF  utility  allows  to  manipulate  a  local   terminal
definition  table which is volatile (in core memory).  The local table
can be initialised with the command DEFAULT or can  be  read  from  an
external  file  using  the commands USE and READ.  The target terminal
name is defined by the commands NAME1 and NAME2.

     The language PARAMS\ is designed to  set  up  or  to  modify  the
current  terminal  parameters  in the local table.  The language TEST\
allows to experiment the validity of the local  table  definitions  on
the target terminal.

     Do not forget to issue the command WRITE in  order  to  save  the
local table into some external BDTF file of your choice.

     Other commands of language GTVDEF\ allow to maintain BDTF  files.
Command  LIST  is very useful to dump the contents of a BDTF file in a
readable format suitable for later input by the GTVDEF utility.
1 WRITE
          [GTVDEF\]WRITE

     WRITE writes terminal parameters from the local  parameter  table
to the current Binary Terminal Definition File (BDTF, see USE).

     Current primary and secondary terminal names are used (see  NAME1
and  NAME2),  and checked against any ambiguity with existing terminal
names in the BTDF file.  If the terminal name is already present,  its
definition is updated.

     The total number of terminal definitions in a BTDF is limited  by
the NTMX built-in parameter (currently 32).
