> * file names could only be 8-byte strings initially and then this was extended* At least part of that is not true. The ‘popular’ MS-DOS 8.3 form derives via

> * file names could only be 8-byte strings initially and then this was extended* At least part of that is not true. The ‘popular’ MS-DOS 8.3 form derives via CP/M from DEC OSes which used 6 character file names and 3 character file types, due to their use of RAD50¹ to fit 3 characters in a 16- or 18-bit word. The type field always existed, so the word ‘extension’ most likely refers to its presentation on the end of the file name, rather than an addition to a previous format. ¹ https://en.wikipedia.org/wiki/DEC_RADIX_50 https://en.wikipedia.org/wiki/DEC_RADIX_50