MS-DOS, " Microsoft Disk Operating System "
Achei  este link com algumas aplicações antigas

https://pt.wikipedia.org/wiki/MS-DOS

https://copy.sh/v86/?profile=msdos
https://www.pcjs.org/software/pcx86/sys/dos/microsoft/6.22/
https://copy.sh/v86/?profile=msdos
https://msdos.org/