INT 21 - DOS 1+ - READ CHARACTER FROM STANDARD INPUT, WITH ECHO
AH = 01h
Return: AL = character read
Notes:  ^C/^Break are checked, and INT 23 executed if read
character is echoed to standard output
standard input is always the keyboard and standard output the screen
under DOS 1.x, but they may be redirected under DOS 2+
SeeAlso: AH=07h,AH=08h,AH=0Ah

See also: 2106

2101 - DOS 1+ - READ CHARACTER FROM STANDARD INPUT, WITH ECHO