@willie959 If you've ever used DOS 1.0, it was CP/M 16 bit. The directory structure, commands, all identical to CP/M.

@willie959 I got to tell you a story about Bill Gates in the early days. Back in the early 80's there were a handful of dial-up BBS's, bulletin board systems. One of them was written and run by a fellow named Jeff Prothero who went by the name Cynbe Ru Taran. His BBS was unique as it was a room system written in C, the popular language for BBS's in that day was BASIC, usually Microsoft BASIC which actually was a port of Dartmouth BASIC. I had disassembled the Z-80 version to see how the interpreter worked, and wrote a similar language that had communications extensions, but in the process I discovered two things, one the keyboard scan routine consumed a horrid 40% of available CPU time, I fixed that, and val(%something) would cause BASIC to explode. I fixed that. Bill Gates and I were both users of this BBS and had some communications. I offered him my fixes absolutely free, he refused them. Would have made MS Basic run 40% faster for millions of users and fixed a nasty bug, would have cost him nothing. So that was my early introduction to the type of person he was.