LDI  0x00       ' Clear screen colour
        ST   0x34       ' t    
        
        LDI  0x08       ' Load screen address 0x0800 high 0x08  
        ST   0x31       ' q
        LDI  0x78       ' Load screen Y dimension, (120)       
yloop   ST   0x33       ' s    
            
        LDI  0x00       ' Load screen address 0x0800 low 0x00
        ST   0x30       ' p
        LDI  0x9f       ' Load screen X dimension, (160)       
xloop   ST   0x32       ' r
            
        LD   0x34   
        XORI 0xff       ; Toggle colour
        ST   0x34   
        POKE 0x30       ; Write low byte of accumulator there
            
        INC  0x30       ; X loop
        LD   0x32   
        SUBI 0x01  
        BNE  xloop      ; Branch (address & 0x00FF) - 2
            
        INC  0x31       ; Y loop
        LD   0x33    
        SUBI 0x01  
        BNE  yloop      ; Branch (address & 0x00FF) - 2
        
forever BRA  forever    ; Branch (address & 0x00FF) - 2