Codes 0x00 to 0x1F are called control codes (and in some contexts (such as use of ASCII control codes with TRON character set) 0x20 is also considered to be a c

Codes 0x00 to 0x1F are called control codes (and in some contexts (such as use of ASCII control codes with TRON character set) 0x20 is also considered to be a control code). The code 0x7F is also a control code. (The PC character set (which is a superset of ASCII) has graphics for those codes as well, although in plain ASCII there are no graphics for the control codes.)