Happy 40th birthday, ZMODEM! On May 20, 1986 the ZMODEM protocol specification was posted on Usenet by Chuck Forsberg of Omen Technology.

https://www.tuhs.org/Usenet/comp.sources.unix/1986-May/004372.html

If you used a BBS before the Internet you might get nostalgic. Otherwise you probably have no idea what this is about (and that’s fine).