.title ctrlc
		$IODEF

		.psect ctrlc_data, long,wrt,noshr,noexe

CTRLC_PRESSED::	.blkl

chan:		.word 0
iosb:		.blkw 4
syscommand:	.ascid "SYS$COMMAND:"


		.psect ctrlc_code, long,nowrt,exe,shr

;
; Enable the AST
;
		.entry CTRLC_TRAP_ON, ^M<>
		clrl CTRLC_PRESSED			; clear flag
		movl #1, R0
		tstw chan				; if first time then...
		bneq 1$
		$ASSIGN_S chan=chan, devnam=syscommand	; ... assign channel
		blbc R0, 2$				; error in assign?
1$:		bsb queue_ast				; queue AST
2$:		ret


;
; Queue the AST
;
queue_ast:	$QIOW_S chan=chan, func=#IO$_SETMODE!IO$M_CTRLCAST, -
			iosb=iosb, p1=CTRLC_TRAP_AST	; queue AST
		blbc R0, 1$				; error in QIO?
		cvtwl iosb, R0				; return iosb status
1$:		rsb


;
; AST to set CTRLC_PRESSED 
;
		.entry CTRLC_TRAP_AST, ^M<>
		movl #-1, CTRLC_PRESSED			; set flag to true
		bsb queue_ast				; requeue the AST
		ret


		.end