The debugger displays output and receives user input through a serial communication port of the computer on which it runs. To use the debugger, you must connect the null-modem cable from this serial port to either a serial terminal or the serial port of another computer. A three-wire null modem cable is the minimum cable requirement for this connection. Typically, users connect the cable to a second computer and use their favorite serial communications software to connect to the serial port and interact with the debugger. The Windows 95 operating system comes with the serial communication program Hyperterminal.