Interrupt 2Ah   Microsoft Networks - Session Layer Interrupt 
	   *    (not documented by Microsoft) 
 
entry   AH      00h     check to see if network BIOS installed 
			return  AH       0 if installed 
		01h     execute NETBIOS request 
		02h     set net printer mode 
		03h     get shared-device status (check direct I/O) 
			AL      00h 
			DS:SI   pointer to ASCIIZ disk device name 
			return  CF      0 if allowed 
		04h     execute NETBIOS  
			AL      0 for error retry 
			        1 for no retry 
			ES:BX   pointer to network control block 
			return  AX      0 for no error 
			        AH      1 if error 
			        AL      error code 
		05h     get network resource information 
			AL      00h 
			return  AX      reserved 
			        BX      number of network names 
			        CX      number of commands 
			        DX      number of sessions 
		06h     Network Print-stream Control 
			note    NETBIOS 1.10 
		20h     unknown 
			note    AL=01h intercepted by DESQview 2.0 
		80h     Begin DOS Critical Section 
			AL      1 to 6 
		81h     End DOS Critical Section 
			AL      1 to 6 
		82h     Server Hook 
			return  unknown 
                        note    called by the Int\21 function dispatcher
			        in DOS 3.10+ for function 0 and functions 
			        greater than 0Ch except 59h 
		84h     keyboard busy loop 
                        note    similar to DOS's Int\28

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