INT 68 - APPC/PCIBM PC - CHANGE LOGICAL UNIT
	AH = 03h subfn 2A00h
	DS:DX -> control block (see #03701)
Return: control block updated


Format of APPC/PCIBM PC "Change Logical Unit" control block:
Offset	Size	Description	(Table 03701)
 00h 12 BYTEs	reserved
 0Ch	WORD	2A00h (verb "Change Logical Unit")
 0Eh  6 BYTEs	00h
 14h	DWORDDoubleword; four bytes.	 Commonly used to hold a 32-bit segment:offset or selector:offset address.	(big-endian) return code (see #03668)
 18h	WORD	00h
 1Ah  8 BYTEs	(big-endian) logical unit ID
 22h	DWORDDoubleword; four bytes.	 Commonly used to hold a 32-bit segment:offset or selector:offset address.	pointer to CREATE_TP_EXIT routine
		00000000h queue ALLOCATEs
		FFFFFFFFh reject incoming ALLOCATEs
 26h	DWORDDoubleword; four bytes.	 Commonly used to hold a 32-bit segment:offset or selector:offset address.	00000000h
 2Ah	DWORDDoubleword; four bytes.	 Commonly used to hold a 32-bit segment:offset or selector:offset address.	pointer to SYSTEM_LOG_EXIT routine, FFFFFFFFh= don't log errors
 2Eh	DWORDDoubleword; four bytes.	 Commonly used to hold a 32-bit segment:offset or selector:offset address.	00000000h
 32h	BYTE	maximum TPs
 33h	BYTE	00h stop QUEUE_ALLOCATEs
		01h resume QUEUE_ALLOCATEs
 34h	DWORDDoubleword; four bytes.	 Commonly used to hold a 32-bit segment:offset or selector:offset address.	pointer to LU_LU_PASSWORD_EXIT routine, FFFFFFFFh = no exit
 38h	DWORDDoubleword; four bytes.	 Commonly used to hold a 32-bit segment:offset or selector:offset address.	00000000h