OK, thanks. I'll look this weekend. The reason I asked was because I recalled an Andrew Pitts's YT video:
https://www.youtube.com/watch?v=3iwKFDER494
where he discusses and shows how he get's into his Desktop's control board (which also has a controller card with USB port) for
a problem he had. Thank you for the clarification. I'm thinking there was a VFD manual in all the packings, so I'll check further.