ZMODEM is a file transfer protocol developed by Chuck Forsberg in 1986, in a project funded by Telenet in order to improve file transfers on their X.25 network. In addition to dramatically improved performance compared to older protocols, ZMODEM also offered restartable transfers, auto-start by the sender, an expanded 32-bit CRC, and control character quoting supporting 8-bit clean transfers, allowing it to be used on networks that would not pass control characters.https://en.wikipedia.org/wiki/ZMODEM
Most of the BBSes out there use the zmodem-protocol for filetransfers from and to the BBS. I decided to implement it into the terminal for compatiblibility.
It was not an easy job for me to implement it but in the end it works very well.