Programming is more than just logic.
Thinking back oh so many years ago when the internet was not universal yet and everyone used dial-up bulletin board systems to communicate with. There was a lot of messaging as there is today. When it came to file transfer, that was another story. At that time, the only way to download a binary file was to download a file full of hex data. The hex data ascii file was then converted to the binary file. There was no error checking so that if you have line noise and extraneous data was captured, you usually had to recapture the file. Not fun especially with large files and slow download speeds. Eventually. There was a file transfer technique known as xmodem that would allow portions (known as packets) of the file to be downloaded and checked for integrity till the full file was downloaded. But there laid a small problem, My commercial terminal program for the commodore 64 did not support xmodem. Knew how to program the hardware to get get and send data, so then ...