Welcome to 16bitos.com. This website showcases the world's largest-known DOS collection and forensic study of individual releases. Through our efforts, we offer researchers and collectors an authoritative summary found nowhere else on the Internet. Several years have been spent on the research, acquisition, and assembly of this project - 16bitos offers you the opportunity to explore the entire DOS catalog from 1981 to 1998.

All data on this site was gathered in our own lab. We used four generations of computer systems and all original media, producing authoritative results we could personally validate and publish. In the course of our product research, we worked with IBM® and Microsoft® directly, as well as collaborating with recognized experts in the field. These were the actual programmers and scientists that developed the disk operating system, as well as leading academic and industry sources that have contributed to the DOS knowledgebase.

16bitos.com is built around an extensive collection that is showcased in each version on this site. Every version we summarize includes label shots, boot screens, package shots, part numbers, file listings, chkdsk summaries, release dates, disk geometry, boot file MD5's, Hex dumps, and specific release information.

DOS Genealogy provides thought-provoking clues to the past. It was the operating system that brought the business and consumer PC market to critical mass in the mid-to-late 1980s. At the time of its arrival, computer memory was measured in bytes and hard drives were not even a system option - by today's standards it was exceptionally primitive. But the engineers and businessmen of that time were important pioneers, and many remain in the tech sector today as powerful influences continuing to shape the destiny of the industry. One way or another, it was DOS that got them there.

We welcome you to explore for yourself the fascinating world of DOS genealogy. I sincerely hope you find your visit to this site insightful and rewarding. Our intention is to be a goodwill ambassador to the online DOS research and collecting community.

Brian Hardy, Project Curator
Email: curator@16bitos.com

Terms of Website Usage

The content on this site is protected by trademark and copyright law by the manufacturers. We collaborated with Microsoft® Corporation and IBM® regarding our legal obligations to the manufacturers. We have designed the content and format of this site to the extent that it complies with "fair use" policies. As a user of this site, you have the obligation to read the Conditions of Use page at the top of the menu to familiarize yourself with these conditions and your responsibilities. Please take the time to do this at your earliest opportunity.


If this is your first-time use of our site, we recommend you begin with the START HERE section. This will establish the ground rules and contains frequently asked questions that cover the most common information about DOS versions.

Missing Versions

While we maintain that our collection efforts have been the most comprehensive ever made, there are three remaining versions we have not found. After several years of attempting to acquire them through original programmers, vendors, and collectors, we are now confident that MS-DOS 2.01 OEM NEC, MS-DOS 2.25 OEM, and MS-DOS 4.0 Mutlitasking will never be found and are lost to the ages. If you or someone you know has access to any or all of these releases, we offer a reward for their submission. Please contact us at: curator@16bitos.com for more information.