Category: serial I/O

INT 14 - Digiboard DigiCHANNEL PC/X* - GET TRANSMIT BUFFER FREE SPACE

	AH = 12h
	DX = port number (00h-03h) (04h-43h for XAPCM232.SYS)
Return: AX = number of bytes free
SeeAlso: AH=0Ah"Digiboard",AH=14h"Digiboard"