Timeline of DOS operating systems
url: https://web.archive.org/web/20160410052452/http:/www.freedos.org/technotes/press/2000-drdos-hist.txt
url: https://web.archive.org/web/20160506004555/http:/www.patersontech.com/dos/origins-of-dos.aspx
date: May 2019
cs1 dates: y
date: 2016-04-10
subject: Category:Computing timelines
subject: Category:DOS on IBM PC compatibles
date: 2016-05-06