.TITLE	CLEAR
;
; FORTRAN-CALLABLE ROUTINE TO CLEAR THE SCREEN OF A CRT TERMINAL.
; THIS CODE IS SPECIFICALLY FOR A BEEHIVE 100 TERMINAL AND MAY HAVE
; TO BE MODIFIED WHERE COMMENTED FOR OTHER TERMINALS.
;
;    CALLING SEQUENCE
;
;      CALL CLEAR([LUN])
;
;         LUN = LUN NUMBER (OPTIONAL INPUT - DEFAULT=5)
;
; WRITTEN   SEPTEMBER 1977   R. B. FRENCH
	.PSECT	DATA,RW,D
;
;************************************************************************
;									*
; THE FOLLOWING CODE IS SPECIFICALLY FOR A BEEHIVE 100 TERMINAL AND	*
; MAY HAVE TO BE MODIFIED FOR OTHER TERMINALS.				*
;									*
KODE:	.BYTE	33,110,33,112			;ESCSEQ TO CLEAR SCREEN	*
;									*
;************************************************************************
;
NKODE=.-KODE
	.MCALL	DIR$,QIOW$
	.PSECT
CLEAR::	TSTB	(R5)		;LUN NUMBER INPUT?
	BEQ	10$		;BRANCH IF NOT
	MOV	@2(R5),QIOW+Q.IOLU ;PUT LUN NUMBER IN DPB
10$:	DIR$	#QIOW		;ISSUE QIO DIRECTIVE TO CLEAR SCREEN
	RTS	PC		;AND RETURN
	.PSECT	DATA,RW,D
;
QIOW:	QIOW$	IO.WLB!TF.WAL,5,1,,,,<KODE,NKODE> ;QIOW DPB FOR WRITE-PASS-ALL
	.END