INT 21 - DR PalmDOS - GENERIC IOCTL - LOGIN SECURITY                            
	AX = 440Dh
	CX = EDC1h (category code EDh, minor code C1h)
	BL = boot drive number (01h=A:,02h=B:,etc)
Return: AL = 0 if already logged in
	AL <> 0 if system is still secured (not logged in)
	ES:DI -> ???
Notes:	This function is called by DR PalmDOS IBMBIO.COM after CONFIG.SYS
	  processing has finished and it has launched the LOGIN.SYS utility
	  (if this is not in the root of the boot drive, the undocumentedInformation about a product which is not publicly available from the manufacturer, and must be determined by reverse-engineering (disassembly, trial-and-error, etc.).	 Undocumented information tends to change -- often dramatically -- between successive revisions of a product, since the manufacturer has no obligation to maintain compatibility in behavior which is not explicitly stated.
	  CONFIG.SYS LOGIN directive can be used to change the path and the
	  moment when the login prompt will be displayed).
	If security is active and the user has still not logged in,
	  IBMBIO.COM will display an error message and halt the system.