An old-school shell hack on a line printer

A fun retro computing hack that turns a dot matrix line printer (Epson LX-350) into an old-school TTY shell. Using Go, the author sets up a pseudo-terminal (pty), runs /bin/sh inside it, and pipes output to the printer via /dev/usb/lp9. The code handles paper feed timing with Epson-specific ANSI escape sequences, spooling paper out when output is ready and back in when more input is expected. The result mimics how Unix terminals worked in the early days of computing.