Manual · Section 2 of 8
The terminals
The console, tty01–tty07, and why there are windows rather than tabs.
Nine ways in
The machine has an operator console and eight terminal lines, and ipnx lets you open all of them. This is not a metaphor: they are real lines on an emulated DZ11 serial multiplexer, each with its own getty, each independently loggable-in. Log in twice on different lines and you have two sessions on one machine, exactly as two people at two desks would have had.
| Line | Terminal | What it is for |
|---|---|---|
console | Operator console | The boot transcript and kernel messages. Read-only. |
tty00 | DMD 5620 | The bitmapped terminal. TERM=dmd. |
tty01–tty06 | vt100 | Ordinary glass terminals, 80×24. |
tty07 | vt100w | A wide one, 132 columns. |
Why the console is read-only
Because on this machine it genuinely is. Eighth Edition's /etc/ttys runs nogetty on the console, so there is nothing there to type at — the boot messages arrive, and that is all it does. Presenting it as an input you could use would be a lie about the machine, so it is shown behind a lock.
Windows, not tabs
Terminals are grouped into windows by shape: the 5620 in one, the 80-column vt100s in another, the 132-column one in a third. Within a window they are tabs; across shapes they are separate windows.
This is forced rather than chosen. Eighth Edition's kernel predatesTIOCGWINSZ — the mechanism by which a modern terminal tells the system it has been resized — so nothing inside the machine can be told that a window changed size. A terminal is the size it was when it was created, permanently. Mixing an 80-column and a 132-column session in one resizable window would mean one of them was always wrong.
A tab labelled tty03 really is tty03
Each line gets its own port on the emulated multiplexer, so the label tells you the truth. It matters more than it sounds: the login profile picks TERM from which line you are on, so if connections landed on arbitrary lines the machine's idea of what terminal you were using would depend on the order you opened tabs.
Closing one
Closing a window hangs up its lines, exactly as unplugging a terminal would. The session ends, the shell gets a hangup, and getty starts again on that line ready for the next login. Nothing else on the machine notices.
Closing the 5620's window has a second effect worth knowing: it stops that emulated processor entirely and gives the CPU back. See the DMD 5620.