INT E0 - ConcCP/MConcurrent CP/M by Digital Research, now DR Multiuser DOS,DR Multiuser DOS - "Q_OPEN" - OPEN MESSAGE QUEUE
	CL = 87h
	DS:DX -> queue parameter block (QPB) (see #04044,#04045)
Return: AX = status (0000h success, FFFFh failure)
	CX = error code (see #04021)
Note:	also supported by REAL/32
SeeAlso: INT E0/CL=86h,INT E0/CL=88h,INT E0/CL=89h


Format of DR Multiuser DOS queue parameter block:
Offset	Size	Description	(Table 04044)
 00h	WORD	internal use, initialize to zero
 02h	WORD	queue ID (set by INT E0/CL=87h)
 04h	WORD	internal use, initialize to zero
 06h	WORD	offset of queue message buffer
		(REAL/32) if FFFFh, then full address of buffer is stored at
		  offest 10h
 08h  8 BYTEs	queue name
---REAL/32 only----
 10h	DWORDDoubleword; four bytes.	 Commonly used to hold a 32-bit segment:offset or selector:offset address.	segment:offset of queue message buffer
SeeAlso: #04045


Format of protected-mode REAL/32 Queue Parameter Block (QPB):
Offset	Size	Description	(Table 04045)
 00h	WORD	internal use
 02h	WORD	queue ID
 04h	WORD	internal use
 06h	DWORDDoubleword; four bytes.	 Commonly used to hold a 32-bit segment:offset or selector:offset address.	32-bit offset to buffer
 0Ah	WORD	selector for buffer
 0Ch  8 BYTEs	queue name
SeeAlso: #04044