INT 21 P - Phar Lap 386/DOS-Extender - CALL REAL-MODE PROCEDURE                 
	AX = 250Eh
	EBX = CS:IP(Internet Protocol) The lower level (transport layer) of the TCP/IP protocol suite.	See also TCP, TCP/IP. of real-mode procedure to call
	ECX = number of two-byte words to copy from protected-mode stack
	      to real-mode stack
Return: CF clear if successful
	    all segment registers unchanged
	    all general registers contain values set by real-mode procedure
	    all other flags set as they were left by real-mode procedure
	    stack unchanged
	CF set on error
	    EAX = error code
		01h not enough real-mode stack space
Note:	this function is also supported by FlashTek X-32VM; under X-32VM, the
	  call will fail if ECX > 0000003Fh
SeeAlso: AX=250Dh,AX=2510h,AH=E1h"OS/286",INT 31/AX=0301h