INCLUDE/NL [314,6]DEFIN
INCLUDE [314,6]VTDEFIN.RAT

#
# VTCURS - SUBROUTINE TO DO RELATIVE CURSOR MOVEMENTS
#
   SUBROUTINE VTCURS (LINES, COLS)
#
   INTEGER LINES		#NUMBER OF LINES TO MOVE
   INTEGER COLS		#NUMBER OF COLUMNS TO MOVE
# NEGATIVE FOR UP OR LEFT; POSITIVE FOR DOWN OR RIGHT
#
   IF (LINES != 0)
      DO I=1,IABS(LINES) [
         CALL VTSEND(ESCAPE)
         IF (LINES > 0)
            CALL VTSEND (DOWN)
         ELSE
            CALL VTSEND (UP)
         ]
   IF (COLS != 0)
      DO I=1,IABS (COLS) [
         CALL VTSEND (ESCAPE)
         IF (COLS > 0)
            CALL VTSEND (RIGHT)
         ELSE
            CALL VTSEND (LEFT)
         ]
   CALL VTSEND (FLUSH)		#FORCE IMMEDIATE OUTPUT
   RETURN
   END

#
# VTDCA - SUBROUTINE TO DO DIRECT CURSOR ADDRESSING ON VT52
#
   SUBROUTINE VTDCA (LINE, COL)
#
   INTEGER LINE
   INTEGER COL
#
   CALL VTSEND (ESCAPE)
   CALL VTSEND (DIRECT)
   CALL VTSEND (31+LINE)
   CALL VTSEND (31+COL)
   CALL VTSEND (FLUSH)		#FORCE IMMEDIATE OUTPUT
   RETURN
   END

#
# VTFUNC - SUBROUTINE TO EXECUTE ESCAPE SEQUENCE FUNCTIONS ON VT52
#
   SUBROUTINE VTFUNC (FUNC)
#
   CHARACTER FUNC		#THE VT52 CONTROL CODE DESIRED
#
# WORKS FOR THE FOLLOWING VT52 FUNCTIONS:
#  HOLD, NOHOLD		HOLD SCREEN MODE
#  ALTKP, NOALTKP		ALTERNATE KEYPAD MODE
#  ERASEL, ERASES		ERASE FROM HERE TO END OF LINE, SCREEN
#  HOME			MOVE CURSOR TO UPPER LEFTHAND CORNOR
#  GRAPH, NOGRAPH		GRAPHICS MODE
#  UP, DOWN			MOVE CURSOR UP OR DOWN 1 LINE
#  RIGHT, LEFT		MOVE CURSOR RIGHT OR LEFT 1 COLUMN
#
#
   CALL VTSEND (ESCAPE)
   CALL VTSEND (FUNC)
   CALL VTSEND (FLUSH)		#FORCE IMMEDIATE OUTPUT
#
   RETURN
   END

#
# VTLABL - SUBROUTINE TO WRITE VERTICALLY ON THE VT52
#
   SUBROUTINE VTLABL (OUTBUF)
#
   CHARACTER OUTBUF(1)
#
# CURSOR MUST FIRST BE MOVED TO STARTING POSITION ON SCREEN
#
   FOR (I=1; OUTBUF(I) != EOF; INCREMENT(I)) [
      CALL VTSEND (OUTBUF(I))
      CALL VTCURS (1,-1)	#BACKUP 1 COL AND GO DOWN 1 LINE 
      ]
   RETURN
   END

#
# VTSEND - SUBROUTINE TO BUFFER AND SEND CHARACTERS TO THE VT52
#
   SUBROUTINE VTSEND (CHAR)
#
INCLUDE CVTLIB
   CHARACTER CHAR, BUFR(40)
   DATA LAST /0/
#
   IF (CHAR != FLUSH) [
      INCREMENT (LAST)
      BUFR(LAST)=CHAR
      ]
   IF (LAST >= 40 \ CHAR == FLUSH) [
      WRITE (VTLUN,1) (BUFR(N),N=1,LAST)	;	1 FORMAT ($,"+",40A1)
      LAST=0				#RESET COUNTER
      ]
#
   RETURN
   END