Format of APPC/PC "Attach Physical Unit" control block:
Offset	Size	Description	)
 00h 12 BYTEs	reserved
 0Ch	WORD	2000h (verb "Attach Physical Unit")
 0Eh  6 BYTEs	00h
 14h	DWORD	(big-endian) return code (see #03668)
 18h	WORD	00h
 1Ah	BYTE	version
 1Bh	BYTE	release
 1Ch  8 BYTEs	(big-endian) net name
 24h  8 BYTEs	(big-endian) physical unit name
 2Ch  8 BYTEs	00h
 34h	DWORD	pointer to SYSTEM_LOG_EXIT routine, FFFFFFFFh=don't log errors
		(see also AH=01h/SF=2100h)
 38h	DWORD	00h
 3Ch	BYTE	00h RETURN_CONTROL: COMPLETE
		01h RETURN_CONTROL: INCOMPLETE