INT 2F U - DOS 5+ DOSSHELL - TASK SWITCHING API(Application Program[ming] Interface) The defined set of calls which a program may make to interact with or request services of the operating system or environment under which it is running.  Because the inputs and outputs of the calls are well-defined, a program using the API can continue using the identical calls even if the internal organization of the program providing the API changes.???
	AX = 4A05h
	SI = function
	    0000h reset???
	    0001h ???
		ES:BP -> 80-byte buffer containing ???
	    0002h ???
	    0003h ???
	    0004h ???
		BL = ???
	    0005h ???
	    0006h get ???
		Return: ES:SI -> ???
	    0007h get ???
		Return: AX = ???
	    0008h get ???
		Return: DX:AX -> ??? (internal control data of some kind)
	    0009h get ???
		Return: ES:SI -> ??? (apparently identical to function 0006h)
	    000Ah ???
		BL = length of buffer
		ES:BP -> buffer containing ???
	    000Bh get ???
		Return: AX = ???
	    000Ch ???
		BL = ???
		Return: if BL nonzero on entry
			    DX:AX -> ???
			if BL = 00h on entry
			    ES:SI -> ???
Notes:	DOSSHELL chains to the previous handler if SI is not one of the values
	  listed above
	the DOSSWAP.EXE module calls functions 03h,04h,05h,07h,08h,09h,0Ch
	the Windows 3.1 DSWAP.EXE and WSWAP.EXE task switchers use these calls
SeeAlso: AX=4B01h