Don't forget Punter: https://en.wikipedia.org/wiki/Punter_(protocol)
I still think in terms of "SYN/ACK SYN/ACK" pairs when analyzing technology.
I still think in terms of "SYN/ACK SYN/ACK" pairs when analyzing technology.
As a teenager I wrote a few implementations of X/Ymodem and Punter for the C64 in machine code back in the day. I was too poor at that age to afford an assembler.
I also wrote a native X/Ymodem utility for the IBM AS/400. I had to write the CRC calculations in MI (AS/400 machine interface language) in order to get enough performance to make it work well.