Changes
/* Technical information */
&F990 : 0321RLDU : Input A, joystick and buttons
&F991 : 0321RLDU : Input B, joystick and buttons
&F992 : 0000XXXX : Input A, mouse X
&F993 : 0000YYYY : Input A, mouse Y
&F994 : 0000XXXX : Input B, mouse X
&F995 : 0000YYYY : Input B, mouse Y
