Wikipedia contributors. (2024, March 21). George Orwell. In Wikipedia, The Free Encyclopedia. Retrieved March 21, 2024, from https://en.wikipedia.org/w/index.php?title=George_Orwell&oldid=1214783158
86 DOS Version 0.1 C Serial # 11 (ORIGINAL DISK) (archive.org) This is the precursor to MS-DOS and is likely the oldest known version to survive. (I had previously uploaded Version 0.34, which was at the time thought to hold that honor.)