Xmodem

Originally developed in 1977 by Ward Christensen, Xmodem is one of the most popular file-transfer protocols. Although Xmodem is a relatively simple protocol, it is fairly effective at detecting errors. It works by sending blocks of data together with a checksum and then waiting for acknowledgment of the block’s receipt. The waiting slows down the rate of data transmission considerably, but it ensures accurate transmission.

Xmodem can be implemented either in software or in hardware. Many modems, and almost all communications software packages, support Xmodem. However, it is useful only at relatively slow data transmission speeds (less than 4,800 bps).

Enhanced versions of Xmodem that work at higher transmission speeds are known as Ymodem and Zmodem.

Webopedia Staff
Webopedia Staff
Since 1995, more than 100 tech experts and researchers have kept Webopedia’s definitions, articles, and study guides up to date. For more information on current editorial staff, please visit our About page.

Top Articles

The Complete List of 1500+ Common Text Abbreviations & Acronyms

Text Abbreviations reviewed by Web Webster   From A3 to ZZZ we list 1,559 SMS, online chat, and text abbreviations to help you translate and understand...

How to Create a Website Shortcut on Your Desktop

Website Shortcut on Your Desktop reviewed by Web Webster   This Webopedia guide will show you how to create a website shortcut on your desktop using...

Windows Operating System History & Versions

The Windows operating system (Windows OS) refers to a family of operating systems developed by Microsoft Corporation. We look at the history of Windows...

First to Fifth Generations of Computers

Reviewed by Web Webster   Learn about each of the 5 generations of computers and major technology developments that have led to the computing devices that...

Hackerspace Definition & Meaning

What is a hackerspace? A hackerspace, also known as a hacklab, incubator, or hackspace,...

Random Access Memory (RAM)...

Random Access Memory (RAM) reviewed by Web Webster   Random Access Memory (RAM) is a...

OEM – original equipment...

OEM - Original Equipment Manufacturer reviewed by Web Webster OEM (pronounced as separate letters)...