LPT Full Form in Computer

Introduction

"LPT" refers to the Line Printer Terminal, a parallel interface that links computers and printers. Although USB and other interface types have mostly replaced it, the LPT interface was extensively used in the early days of computers.

Data transmission from the computer to the printer was made possible using the LPT port, a 25-pin D-subminiature connection. The LPT port's parallel interface made it possible for speedier data transfer as opposed to the slower serial interface, which was also often utilized. Because of its dependability and simplicity, the LPT interface was widely used to link computers to printers and other peripherals.

Since USB offers faster data transfer rates, more dependable connections, and support for hot-plugging the ability to connect and disconnect devices without shutting down the computer it has supplanted the LPT interface in recent years. Modern operating systems still support the LPT interface, although its use is declining, and new printers and other peripherals are mainly limited to USB ports.

History of LPT

Developed in the early days of personal computing, the Line Printer Terminal (LPT) interface was a standard parallel interface used to connect printers to computers. Early in the 1980s, as personal computers gained popularity and the demand for dependable and quick printer connections increased, the LPT interface was developed.

The serial interface was the most widely used method of connecting printers to computers before the LPT interface. Nevertheless, printing needed fast data transmission rates, and the serial interface was slow and ill-suited to meet those expectations. The LPT interface gained popularity for linking printers and other peripherals to personal computers because it was intended as a parallel interface that could carry data more quickly than the serial interface.

Beyond printing, the LPT interface was a general-purpose input/output (I/O) port, enabling various applications. For instance, the LPT connection was utilized by specific early software applications to manage external hardware components like motors or lights.

The Universal Serial Bus (USB) interface, which provides faster data transfer rates, more dependable connections, and support for hot plugging, has largely supplanted the LPT interface despite its widespread use. Although current operating systems still support the LPT interface, its usage is declining, and new printers and other peripherals are usually only offered with USB interfaces.

Purpose of LPT

LPT's main objective is to give users a means of interacting with computers and printing text-based documents. It offers a communication channel between the user and the system, enabling you to give orders and receive data from the computer.

Main Components of LPT

The following are the primary elements of the Line Printer Terminal (LPT) interface:

• Connector: The physical link between the computer and printer was established using the LPT interface, which generally used a 25-pin D-subminiature connector.
• Data lines: To transfer data between the computer and the printer in parallel, the LPT interface employed 8 data lines. In contrast to the slower serial interface, this enabled quick data transfer.
• Control lines: The computer and printer data flow was managed via the LPT interface using 4 control lines. These lines contained error, busy, acknowledge, and printing signals.
• Ground line: The data and control lines in the LPT interface were referenced to a ground line for voltage calibration.
• Driver Circuit: The driver circuit produced the control signals that went to the printer. Usually, an expansion card is inserted into the computer or the laptop's motherboard housing the driver circuit.

Because of its straightforward and dependable architecture, the LPT interface is widely used to link printers and other peripherals to personal computers. But the Universal Serial Bus (USB) interface, which provides higher data transfer rates, more dependable connections, and support for hot plugging, has essentially supplanted the LPT interface.

Working of LPT

Data is transferred parallel between the computer and the printer using the Line Printer Terminal (LPT) interface. Fast data transfer was made possible by sending a print job from the computer to the printer across eight data lines sent in simultaneously. The LPT interface also utilized four control lines to manage data flow and provide status information between the printer and computer.

A 25-pin D-subminiature connector was typically used in conjunction with the LPT interface to provide the connection between the computer and printer. While the printer's driver circuit generated the control signals that were sent to the printer, the printer's controller was responsible for interpreting the control signals and printing the data that was received on the data lines.

Printers and other peripherals were frequently connected to personal computers over the LPT interface because it was a straightforward and dependable interface. However, the LPT interface has mostly been replaced by the Universal Serial Bus (USB) interface, which offers faster data transfer rates, more stable connections, and support for hot plugging. While the LPT interface is still supported by modern operating systems, its use is dwindling, and new printers and other peripherals are often only available with USB connections.

Benefits of LPT

• Low cost of electronics
• Extremely simple to find ready-made electronic diagrams or cards
• Ability to use/test various program types and on various operating systems (e.g., Mach3 and Kcam4 on Windows or LinuxCNC on Ubuntu)
• Does not require additional cards specific to the program used. If required, all you have to pay is the program's license (LinuxCNC is complimentary, while Mach3 requires approval).

Limitations of LPT

• It makes sense that the computer has a parallel port; however, if it doesn't, you can add one for about 18 euros on the PCI slot.
• A desktop computer is preferred because the LPT port is easier to manage (you can still find used PCs for less than 100 euros).
• WXP and Ubuntu are incredibly reliable and well performer operating systems. However, 64-bit and Windows 8 PCs are probably experiencing issues.

Applications for LPT

Before the widespread adoption of contemporary printing technologies, LPTs were frequently employed in various applications. They were commonly seen in commercial settings where many text-based documents were required to be produced, like banks, government buildings, and data centers. Moreover, LPTs were employed in mainframe computer systems to offer a user interface for system interaction.