.eqv    ISO_LF      10  # Line feed (newline)
.eqv   SYS_PRINT_CHAR   11
    
    #########################################################################
    # Receiver control.  1 in bit 0 means new char has arrived.  This bit
    # is read-only, and resets to 0 when CONS_RECEIVER_DATA is read.
    # 1 in bit 1 enables hardware interrupt at interrupt level 1.
    # Interrupts must also be enabled in the coprocessor 0 status register.
    
 .eqv   CONS_RECEIVER_CONTROL    0xffff0000
 .eqv   CONS_RECEIVER_READY_MASK 0x00000001
 .eqv   CONS_RECEIVER_DATA    0xffff0004

 .eqv   DISPLAY_CONTROL 0xffff0008
 .eqv   CONS_DISPLAY_MASK 0x00000001
 .eqv   DISPLAY_DATA   0Xffff000c
    
    # Main body
	    .text
    main:
    	  	
	    # Spin-wait for key to be pressed
    key_wait:
	    lw      $t0, CONS_RECEIVER_CONTROL
	    andi    $t0, $t0, CONS_RECEIVER_READY_MASK  # Isolate ready bit
	    beqz    $t0, key_wait
    
	    # Read in new character from keyboard to low byte of $a0
	    # and clear other 3 bytes of $a0


	    lbu     $a0, CONS_RECEIVER_DATA
display_wait:
  	    lw $t0, DISPLAY_CONTROL
	    andi $t0, $t0, CONS_DISPLAY_MASK
	    beqz $t0,display_wait
			    
	    sw 	$a0, DISPLAY_DATA  #store it to the display data buffer
		    
	    # Print character and newline  to standard out
    	    # to show it works
	    li      $v0, SYS_PRINT_CHAR
	    syscall
	    
	    li      $a0, ISO_LF
	    li      $v0, SYS_PRINT_CHAR
	    syscall
	    j key_wait