Format of FaxBIOS SYS_LOGIN command buffer:
Offset	Size	Description	)
 00h	WORD	structure size
 02h	WORD	function number
 04h	WORD	return code
 06h	WORD	client ID
 08h	WORD	API Major Version
 0Ah	WORD	API Minor Version
 0Ch	DWORD	reserved for manufacturer's use
 10h 22 BYTEs	manufacturer's ID
 26h	WORD	highest possible device number
 28h	WORD	maximum destinations per envelope
 2Ah	WORD	maximum files per envelope
 2Ch	WORD	FaxBIOS capabilities (see #02933)
 2Eh	DWORD	T.30 capabilities (see #02934)
 32h	WORD	IPC handle
 34h	DWORD	amount of memory needed to load
 38h	WORD	scope (00h for public, nonzero for private)
 3Ah  6 BYTEs	future expansion
 40h	WORD	structure size