Function 02h Display OutputOutputs char in DL to STDOUT
entry AH 02h
DL 8 bit data (usually ASCII character)
return none
note 1) If char is 08 (backspace) the cursor is moved 1 char to the left
(nondestructive backspace).
2) If Ctrl-C is detected after input, int 23h is executed.
3) Input and output are redirectable. If redirected, there is no way to
detect disk full.