A Serial Printer is a type of printer that connects to a computer through a serial port. Serial ports, often referred to as COM ports, facilitate serial communication whereby data is transmitted sequentially one bit at a time via a single channel.
Functionality and Operation
Serial printers receive data from a computer or other digital device over a serial interface. This means data bits are sent one after another, over a single wire, typically following regulated protocols such as RS-232. Key characteristics include:
- Communication Speed (Baud Rate): The rate at which data is transferred, typically measured in bits per second (bps).
- Data Format: Includes start bits, stop bits, parity bits, and data bits, which ensure error-free communication.
- Hardware Interface: Often uses a DB-9 or DB-25 connector.
Historical Context
Serial printers were predominantly used in the earlier days of computing, where robust and straightforward communication protocols were essential. Originating in the late 1960s and gaining popularity through the 1980s, they were widely integrated with mainframe and early personal computing platforms. The simplicity of the serial interface made these printers relatively easy to implement and troubleshoot.
Types of Serial Printers
- Dot Matrix Printers: Widely used for printing continuous feed documentation and forms.
- Thermal Printers: Common in fax machines and cash registers, these printers employ heat-sensitive paper.
- Line Printers: Mostly used in large-scale data centers for high-volume printing tasks.
Special Considerations
- Baud Rate Settings: Mismatched baud rates between printer and computer can lead to communication errors.
- Buffer Capacity: Limited buffer size in older printers could result in data overflow.
- Cable Length: Longer serial cables are prone to signal degradation, requiring proper shielding and EQ (equalization) techniques.
Examples
A class of serial printers includes models like the IBM 1403 printer, which utilized serial interfaces for high-speed data processing tasks in enterprise environments.
Applicability in Modern Technology
While serial printers have largely been superseded by USB and network-based printers, they still find niche applications in embedded systems, industrial environments, and legacy systems where established workflows rely on serial communication.
Comparisons
- Serial vs. Parallel Printers: Serial printers use a single channel for data transfer, while parallel printers use multiple channels, usually resulting in faster data transmission.
- Serial vs. USB Printers: USB ports offer higher data transfer speeds and better plug-and-play functionality compared to serial ports.
Related Terms
- Serial Port: A physical interface through which data is transferred one bit at a time.
- Baud Rate: The symbol rate or modulation rate of data transfer in symbol changes per second.
- RS-232: A standard for serial communication transmission of data.
FAQs
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Why did serial printers become obsolete? Serial printers became less common due to advancements in faster and more efficient data transfer technologies like USB and network interfaces.
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Can a modern computer use a serial printer? Yes, with the use of USB-to-serial adapters, modern computers can interface with serial printers.
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What are common uses for serial printers today? They are used in environments where legacy system compatibility and reliability are critical, such as industrial automation and some retail point-of-sale systems.
References
- “The Evolution of Serial Communication” by J. Allen, 1987.
- “Computer Interfaces: A History of Data Transfer” by R. Clarke, 1999.
- RS-232 Standards and Protocols, ANSI, 1969.
Summary
Serial printers, once a cornerstone of computer peripherals, played a crucial role in the evolution of computer hardware interfaces. Though largely outdated by modern standards, understanding their function and history sheds light on the development of data communication technologies.
