Notation and terminology

• User input looks like this.
• Program output, file names, etc looks like this.
• Octal is often the default number base.
• Altmode means ASCII ESC, octal code 33. On screen it's printed as $ or ◊.
• Control characters are printed like ^X or ↑X.
• On old terminals, ^ and _ look like ↑ and ←. This is due to the 1963 version of ASCII.
• On a Knight TV keyboard, there is a CALL key which is used throughout in place of ^Z. On the emulator F1 is used for CALL.
• Job is a running program.