If the word length is less than 8 bits, all unused bit(s) will be assigned a value of zero.

If a GET# does not find any data in the buffer, the character "" (a null) is returned.

If INPUT# is used, then the system will hang in a waiting condition until a non-null character and a following carriage return is received. Therefore, if the Clear To Send (CTS) or Data Set Ready (DSR) line(s) disappear during character INPUT#, the system will hang in a RESTORE-only state. This is why the INPUT# and CHRIN routines are NOT recommended.

The routine CHKIN handles the x-line handshake which follows the EIA standard (August 1979) for RS-232-C interfaces. (The Request To Send (RTS), CTS, and Received line signal (DCD) lines are implemented with the Commodore 64 computer defined as the Data Terminal device.)