C
C============================================================================
C
C	Graphics driver for HP 7470A plotter
C
C	10.22" x 7.5"		(10300 x 7650)
C
C============================================================================
C
	JDEV = JDEV - 1
	IF (JDEV .NE. 0) GOTO 4999
C
	IF ((IMODE .LT. -5) .OR. (IMODE .GT. 7)) RETURN
	GOTO (4000,4005,4010,90,90,4020,4030,4040,4030,4080,4090,
	1				4200,4110), IMODE+6
C
C	mode -5: we exist
C
4000	X = 1.0
	GOTO 90
C
C	mode -4: initialize
C
4005	CALL GTATT(LUNGRP)		! attach the device
	CALL GT('IN;SP1;PA;')		! initialize, select pen 1
	CALL GT(ESCAPE)			! <ESC>
	CALL GT('.H40;0;17:;')		! establish DEC style handshake
	CALL GT(ESCAPE)
	CALL GT('.N;19:;VS;')		! and make the fastest drawing speed
	CALL GTF			! flush the buffer
	LINPAT = -1			! init sets the line pattern
	NIBS = 1			!  and the nibs
	GOTO 90
C
C	mode -3: return paper size (active area on 8.5" x 11" paper)
C
4010	X = 10.22
	Y = 7.5
	GOTO 90
C
C	mode 0: clear the 'screen'
C
4020	GOTO 90
C
C	modes 1,3: unwritten vector, point plot
C
4030	CALL GT('PU')			! pen up
	GOTO 4050
C
C	mode 2: written vector
C
4040	CALL GT('PD')			! pen down
C
C	modes 1,2,3: ship out the coordinates
C
4050	IX = MIN1(10300.,AMAX1(0.,1007.8*XT+0.5))
	IY = MIN1( 7650.,AMAX1(0.,1020.0*YT+0.5))
	ENCODE (11,4060,BUFFER) IX,IY
4060	FORMAT (I5,',',I5)
C	compress the spaces out
	J = 1
	DO 4070 I=1,11
	IF (BUFFER(I) .EQ. "40) GOTO 4070
	BUFFER(J) = BUFFER(I)
	J = J + 1
4070	CONTINUE
	CALL GT(BUFFER,J-1)
	CALL GT(';')
	IF (IMODE .EQ. 3) CALL GT('PDPU;') ! plot a point
	IF (IMODE .EQ. 1) CALL GTF	! on each unwritten vector, we
C					! must make sure the pen is up -
C					! else we might get a splotch of ink.
C					! ie. flush the buffer.  Slow,
C					! but it does assure a clean plot.
	GOTO 90
C
C	mode 4: complete the plot
C
4080	CALL GT('PU;SP0;')		! put the pen away
	CALL GTF			! flush the buffer
	CALL GTATT(-LUNGRP)		! and deattach the plotter
	CALL CLOSE(LUNGRP)
	GOTO 90
C
C	mode 5: nibs (X; right or left pen) and line pattern (Y)
C
4090	IX = X
	IF (IX .GT. 1) IX = 2
	IF (IX .EQ. NIBS) GOTO 4102	! nibs already set - just leave
	NIBS = IX
	IF (NIBS .EQ. 1) GOTO 4100
	CALL GT('SP2;')			! nibs > 1, use right pen
	GOTO 4102
4100	CALL GT('SP1;')			! nibs = 1, use left pen
C
C	now do the line pattern
C
4102	IY = Y
	IF (IY .EQ. LINPAT) GOTO 90	! line pattern set - just leave
	LINPAT = IY
	IY = 0
C	kludge - if octal constant was in the expression, it doesn't work!
	IX = "100000
	IF (LINPAT .EQ. IX) IY = 1	! set up the HP line types
	IX = "176000
	IF (LINPAT .EQ. IX) IY = 2
	IX = "177700
	IF (LINPAT .EQ. IX) IY = 3
	IX = "177772
	IF (LINPAT .EQ. IX) IY = 4
	IX = "177714
	IF (LINPAT .EQ. IX) IY = 5
	IX = "176310
	IF (LINPAT .EQ. IX) IY = 6
	IF ((IY .GE. 1) .AND. (IY .LE. 6)) GOTO 4103
	CALL GT(';LT-1;')		! solid line
	LINPAT = -1
	GOTO 90
4103	ENCODE (5,4104,BUFFER) IY
4104	FORMAT(';LT',I1,';')
	CALL GT(BUFFER,5)
	GOTO 90
C
C	mode 7: select the pen velocity (X)
C
4110	IF ((X .GT. 0.0) .AND. (X .LT. 38.1)) GOTO 4118
	CALL GT(';VS;')				! full speed ahead
	GOTO 90
4118	ENCODE (8,4120,BUFFER) X
4120	FORMAT (';VS',F4.1,';')
	CALL GT(BUFFER,8)
	GOTO 90
C
C	mode 6: identify ourself
C
4200	WRITE (LUN,4210)
4210	FORMAT('+	HP 7470 two pen plotter')
	GOTO 90
C
C	all done - get next device
C
4999	CONTINUE