.TITLE	RDAST
;
; FORTRAN-CALLABLE ROUTINE THAT, ONCE CALLED, WILL INCREMENT A SPECIFIED
; FLAG WHENEVER THERE IS A LINE OF UNSOLICITED INPUT FROM THE TERMINAL.
; RDAST USES THE ATTACH WITH UNSOLICITED READ AST FEATURE (IO.ATA) OF THE
; TERMINAL HANDLER.  IT WAS WRITTEN FOR IAS VERSION 3.0, BUT THE SAME
; FEATURE EXISTS FOR RSX-11D AND RSX-11M.
;
; NOTE: RDAST ONLY INCREMENTS THE SPECIFIED FLAG SIGNIFYING THAT A LINE
; OF TEXT HAS BEEN INPUT.  THE CALLING PROGRAM MUST ISSUE A READ REQUEST
; TO ACTUALLY READ THE LINE OF TEXT.
;
; CALLING SEQUENCE
;
;    CALL RDAST(IAST)
;
;       IAST - FLAG TO BE INCREMENTED WHEN UNSOLICITED INPUT IS AVAILABLE
;
; WRITTEN   MARCH 1979   R B FRENCH   THE BOEING COMPANY
;
	.MCALL	DIR$,QIOW$,ASTX$S
;
RDAST::	MOV	2(R5),ASTFLG	;SAVE THE ASTFLG FLAG ADDRESS
	DIR$	#SETAST		;SET UP FOR UNSOLICITED READ
	RTS	PC
;
SETAST::QIOW$	IO.ATA,1,1,,,,<AST>
;
AST:	INC	@ASTFLG		;INCREMENT THE AST FLAG
	MOV (SP)+,CHAR
	ASTX$S			;EXIT THE AST ROUTINE
;
ASTFLG:	.WORD	0		;
;
ICHAR::
	MOV CHAR,R0
	MOV #-1,CHAR
	RETURN
CHAR:	.WORD -1
	.END