VT52 - A TECO Macro for Video Terminals


     VT52 is a TECO  macro  to  make  use  of  the  VT52  display
terminal;   it implements an interactive keypad editor.  The keys
on the  VT52  keypad  are  used  for  such  functions  as  cursor
movement,   character  deletion  and  space  expansion,  and  the
delimiting of search strings and TECO commands.  Most characters,
when  typed  on  the  keyboard, are simply inserted into the text
buffer at the current cursor position.  The  terminal  screen  is
continuously  maintained  as  a display of the text buffer around
the cursor.

     Executing the TECO command EIVT52$$ causes the macro  to  be
loaded into Q-register I.  Executing Q-register I then starts the
macro, operating on whatever text is in the buffer.  Starting the
macro  with  an argument of -1 (i.e., -1MI$$) causes the macro to
display  a  picture  of  the  keypad  with  descriptions  of  the
functions.

     Needless to say, VT52 is more demanding on system  resources
than  conventional  TECO;  executing the macro uses a substantial
amount of CPU time.  It will run well on a  single  user  system,
but may well be too soggy to use on a loaded multi-user system.

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              Keypad layout                     Other keys
_________________________________________
| "BLUE"  |  "RED"  | "GREY"  |   "^"   |  CTRL/C  Exit from macro
|  Save   |  TECO   | Unsave  |  Up in  |  CTRL/D  Kill rest of line*
|  text*  | command |  text   | column* |  CTRL/K  Kill line*
|_________|_________|_________|_________|  CTRL/U  Kill start of line
|   "7"   |   "8"   |   "9"   |   "v"   |  CTRL/W  Set cursor line*
|  Open   |  Page*  |  Quote  | Down in |  CTRL/Z  Exit from macro
|  line*  |         |  next*  | column* |  BK SP   Go to end of line*
|_________|_________|_________|_________|  DELETE  Delete previous*
|   "4"   |   "5"   |   "6"   |   ">"   |  2 ESC's Repeat TECO command
|   Up    | Delete* | Delete  | Cursor  |
|  line*  |Character|  last   | right*  |       Arguments
|_________|_________|_________|_________|
|   "1"   |   "2"   |   "3"   |   "<"   |  All starred (*) commands
|   Top   | Bottom  |  Start  | Cursor  |  optionally take an argument
| of page*| of page | of line |  left*  |  entered as <ESC>[-]<digits>
|_________|_________|_________|_________|
|        "0"        |   "."   | "ENTER" |
|     Down line*    | Search* | Search  |
|                   |         |argument*|
|___________________|_________|_________|


Notes:

"Save text" (blue key):  Initial pressing of this key copies  the
current  line  into  the  save  buffer  and  advances  one  line.
Subsequent pressing of the key appends additional lines into  the
buffer, until any other key is pressed.

"TECO command" (red key):  The macro clears a line of the display
and  prompts  for  a  TECO  command, which is terminated with the
usual double alt mode.

Searches:  Pressing the "ENTER" key prompts for a search  string;
pressing  the  "."  key  terminates  the string and initiates the
search.  Pressing "." again causes the string last entered to  be
searched again.