Back in university, we had lots of Falco t310 terminals. (VT100-esque terminals connected to a serial port.) Occasionally, I'd accidentally cat an executable f

Back in university, we had lots of Falco t310 terminals. (VT100-esque terminals connected to a serial port.) Occasionally, I'd accidentally cat an executable file to the terminal and it would sometimes switch to a graphical mode and draw lines on the screen like an 80s BASIC program. Clearly there must be some control codes lurking in that executable that coincidentally work as graphical instructions. I tried experimenting with cutting the file up and into pieces to narrow down the magic control codes, but the number of bytes with a value of 7 in that file started annoying the people around me. They replaced those terminals with Windows PCs the next year.