What is nul modem?

A null modem is a type of serial cable that is used to connect two computers or devices directly to each other without the need for a modem or other communication equipment. This type of cable is typically used for serial communication, such as transferring data between two computers or connecting a computer to a printer or other device.

A null modem cable includes wires that are crossed over from one end to the other. This allows the sending and receiving signals to be reversed, so that each device can communicate with the other. The cable may also include other wires for hardware flow control and handshaking, which can help to ensure reliable communication between the two devices.

Null modem cables can typically transmit data at speeds of up to 115,200 bits per second, although some newer cables may support even faster speeds. They can be used with a variety of different devices, including computers running different operating systems, as long as the devices have compatible serial ports.