The Agilent 59401A is a Bus System Analyzer. The 59401A Bus System Analyzer simplifies and speeds up the diagnosis of software and hardware problems by allowing the user to see the status of all bus lines, including the actual characters on the bus data lines. The 59401A can also drive all bus lines, as well as completely exercising another Talker, Listener or Controller. The display monitors all bus lines, represents data lines, any memory location or DIO front-panel switch settings in octal code and ASCII. In the Listen mode, it will store up to 32 characters of bus traffic in memory for real time and repetitive testing. In the Talk mode, the bus lines can be driven directly from front-panel switches or loaded with 32 character sequence. For added convenience, several operating speeds are available including one character at a time, two characters per second, regular bus speed or variable rate.