INT 14 - TelAPI - WRITE BLOCK                                                   
	AH = 06h
	CX = number of characters to write
	DX = port number
	ES:DI -> buffer containing data
Return: AX = number of characters actually sent (negative on error)
	CX = ???
SeeAlso: AH=07h"TelAPI",AH=E0h"TelAPI",AH=E3h"TelAPI"