Format of REAL/32 RCT Control Block for Drives:
Offset	Size	Description	)
 00h	BYTE	command byte
		00h map disk drive
		02h map list device
 01h	BYTE	local resource ID
 02h	BYTE	remote resource ID
 03h	BYTE	server node ID number
Note:	the RCT Control Block is a union of two possible structures; this
	  variant is used when mapping disk drives and list devices
SeeAlso: #04032