Toshiba T2150CD user manual Interfacing for Serial Devices, Security lock

A security lock enables you to anchor your computer and an optional port replicator to a desk or other heavy object to help prevent unauthorized removal of the computer or port replicator.

Attach one end of a cable to the desk and the other end to the security lock slot on the left side of the computer and to the optional port replicator as shown below.

Figure 12-16 Security lock

Interfacing for Serial Devices

The term serial interfacing refers to information being transmitted to a device sequentially, one bit at a time, rather than in parallel, one byte (eight bits) at a time.

RS-232-C is the most common serial interfacing standard in the microcomputer industry. The computer can use most serial devices that meet this standard. See Chapter 2, The Grand Tour, for the location of the serial port. Serial devices can also be connected to an optional port replicator. See the Port replicator section in this chapter.

A serial port’s I/O address and interrupt request level are related to hardware configuration. The microprocessor uses the computer’s I/O ports to specify a unique control register in BIOS-level programs. A control register is the same as a memory address for the port’s location.

MS-DOS logically assigns these names: COM1, COM2, and COM3 to the RS-232-C serial port. The computer allows you to assign either COM1 or COM2 to its port. The computer does not use COM3.

Use the TSETUP program to assign the port names. Refer to Chapter 11, Setup and Password Security, for details.

When you assign a port name, either COM1 or COM 2, the I/O address and interrupt level are automatically selected by the computer.

Documentation supplied with your application programs will tell you which communications parameters to select if required.