.PSECT	DATA,RD,WRT,NOEXE,LONG
DSC_ISUMONMBX:
	.ASCID	\ISUMONMBX\
DSC_ISUDLOMBX:
	.ASCID	\ISUDLOMBX\
CHAN_MBX:
	.BLKW	1

	.PSECT	CODE,RD,NOWRT,EXE,LONG
	.ENTRY	DMBX,^M<R2,R3,R4,R5,R6,R7,R8,R9,R10,R11>

	$ASSIGN_S	CHAN=CHAN_MBX,-
		DEVNAM=DSC_ISUMONMBX
	$CANCEL_S	CHAN=CHAN_MBX
	$DELMBX_S	CHAN=CHAN_MBX

	$ASSIGN_S	CHAN=CHAN_MBX,-
		DEVNAM=DSC_ISUDLOMBX
	$CANCEL_S	CHAN=CHAN_MBX
	$DELMBX_S	CHAN=CHAN_MBX
	$EXIT_S	R0

	.END	DMBX