Format of APPC/PC "Get ALLOCATE" control block:
Offset	Size	Description	)
 00h 12 BYTEs	reserved
 0Ch	WORD	2800h (verb "Get ALLOCATE")
 0Eh  6 BYTEs	00h
 14h	DWORD	(big-endian) return code (see #03668)
 18h	WORD	00h
 1Ah  8 BYTEs	(big-endian) logical unit ID
 22h	BYTE	type (00h dequeue, 01h test)
 23h	DWORD	pointer to CREATE_TP record