@(#)README	1.2

This program prompts the user to enter a string from the keyboard.
However, instead of using the read_string syscall to obtain the
input string, the keyboard should be configured to generate an
interrupt when a key is pressed.
The exception handler should be modified to place each character
as it arrives from the keyboard into register $s6.

In the main program, $s6 should be polled to determine when a new
character has been received.
$s6 should be initialized to 0 by the main program and the
keyboard should be configured to generate interrupts prior to
entering the background loop.
Upon detecting a new character, the background loop should store
the new character in the next slot within an input buffer.
Allow up to 70 characters in the input buffer.

After each new character is placed into the buffer, the buffer
contents should be output on a new line using the print_string
syscall.
$s6 should be reset to 0 so as to allow the detection of the next
character.
There are 4 input characters (newline, backspace, escape and %)
that should cause some special action to be performed:

newline (ascii code 10) generated when the enter key is pressed
	should cause the program to reset the buffer pointer to
	the start of the buffer and prompt the user to enter
	the next input string.
	The buffer should now be considered empty.

backspace (ascii code 8) should erase the previous character from
	the buffer (i.e. replace with a blank) and cause the next
	input character to go into the previous slot.
	Of course, the pointer should not be allowed to backup
	further than the first slot in the buffer.
	This allows erasing input characters prior to hitting
	the enter key.

escape (ascii code 27) generated by the Esc key, should cause the
	program to exit the background loop and terminate.

% (ascii code 37 ) performs a limited editing function based on
	the very next character entered immediately after the %
	as described below:

	B to backup 1 position within the buffer without changing
	the character at that position, but not beyond the start
	of the buffer.

	F to move forward 1 position within the buffer but not
	past the end

	U to capitalize the letter at the current buffer position
	or no effect if the character is not a letter.

	L to convert to lower case the letter at the current
	buffer position or no effect if the character is not
	a letter.

	Any character other than B, F, U, or L following the %
	should simply cause the % and that character to be
	entered into the buffer at the current position.
