To terminate a READ command for terminals with anything other than a carriage return (<CR>) or an escape (<ESC>), use the TERMINATOR deviceparameter with the USE command. By default, terminals recognize the terminators <CR> (ASCII 13) and <ESC> (ASCII 27).

A successful READ operation sets $ZB to the input terminator or terminating escape sequence. For example, if a READ terminates with a <CR>, $ZB equals $C(13). If the READ times out or the input exceeds the maximum length, the terminal device driver sets $ZB to null.