Format of 10NET Who data structure:
Offset	Size	Description	)
 00h  8 BYTEs	user name
 08h 15 BYTEs	node ID
 17h  3 BYTEs	unique portion of Ethernet address
 1Ah	BYTE	Who group number
 1Bh	WORD	service mask (see #03779)
 1Dh	DWORD	serial number
 21h	BYTE	maximum concurrent users with same serial number allowed on net
 22h	BYTE	chat mask (see #03781)
 23h	BYTE	internal system bits (see #03782)
 24h  9 BYTEs	version number in format MM.mm.xxx
 2Dh	BYTE	number of shared directories
 2Eh	BYTE	number of shared printer queues