This is old news. Also, slightly misleading, since it suggests to those that know the old news that MS has released later DOS source code, i.e. 6.22.
So it was built on Assembly language? Always thought it was built using BASIC.
Why would you think that?
Are you sure you're not thinking of something like the Commodore 64 that dropped you inside a BASIC interpreter after boot?
I got it confused with Altair BASIC which gates used to work on.
Is this practical for anything at this point?
I meant this as an honest question. Are there practical uses for this beyond "huh, that's interesting". I can't think of any, but I'm not knowledgeable on OS design, so I'm honestly asking the question.