INT 21 - DOS 1+ - READ CHARACTER FROM STDAUX
AH = 03h
Return: AL = character read
Notes:  keyboard checked for ^C/^Break, and INT 23 executed if detected
STDAUX is usually the first serial port
SeeAlso: INT 14/AH=02h,INT E0/CL=03h

See also: 2104

2103 - DOS 1+ - READ CHARACTER FROM STDAUX