maze.  Use the text characters 
	A, B, C Etc. to represent the disks.  Use three of the four 
	rows on the simulated screen to represent the pillars.
	
30)	Use the keyboard on Port 07. Write an interrupt handler 
	(INT 03) to process the key presses. You must also process 
	INT 02 (the hardware timer) but it need not perform any task. 
	For a more advanced task, implement a 16 byte circular buffer. 
	Write code to place the buffered text on the VDU screen when 
	you press Enter. For an even harder 