Starting and Stopping ITS - larsbrinkhoff/its-manual GitHub Wiki

To start ITS, the computer is bootstrapped from a paper tape which starts the DSKDMP program. This program knows how to transfer programs between memory and files in the ITS file system. The default directory is called . which is where ITS stores all important files related to booting the system. DSKDMP and many other programs in ITS uses commands involving typing the Escape key (called Altmode), which echoes as $ or ◊. For example, to list files, type F$.

ITS files have two names. If you only enter one name, DSKDMP will use it as the second file name and default the first file name to @. Thus many boot files have @ as their first file name. ITS itself is the file @ ITS. To load and start a program just type its name and finish with Enter. Thus, to start ITS, just type ITS, followed by Enter. Another way would be to type L$ITS to load the program, and then G$ to start it.

When ITS has started, nothing happens at first. This is because ITS includes a debugger, the non-timesharing DDT, and this is where ITS goes first. You can exit immediately back to DSKDMP by typing $U, or you can examine the program, set breakpoints, etc. But most likely you just want to start ITS, so type $G.

What happens next is that ITS first runs SALV, the salvager, to check the file system integrity. When finished, ITS will type KA ITS 1651 IN OPERATION and some other text. Now ITS is ready to accept users logging in and use the system.

First, if you have just booted up the system you will still sit at the system console. This teletype will also act as the system log, so it's not recommended to use it to log in. Please select another terminal, for example a Knight TV.

To get ITS' attention on a free terminal, type ^Z (Control + Z) on a regular terminal, or CALL (mapped to F1) on a Knight TV keyboard. ITS will respond by typing some version information, print a welcome message, and start HACTRN. HACTRN is the top-level user interaction program, and is another version of the DDT debugger. You can start using the system immediately...

...but you should really tell the system who you are with the login command. Type a short name and then $U to log in. If you haven't previously registered a user name, ITS will complain about a missing directory, but you can still use the system.

To create a directory for yourself, type ^R name; ..NEW. (UDIR) and then Enter. This is the DDT command for reading a file with a magic name which is how you create a new directory.

When you are done, type $$U to log out.

It's best to shut down ITS properly to let it do house keeping like writing out pending data to the file system. This is done with a program called LOCK. Type LOCK^K to start it and get a _ prompt. Type 5DOWN to have it shut down ITS in five minutes. Do not type Enter right away. LOCK will now ask for confirmation, so answer Y. Now you will be asked for a message to announce the shutdown. Type something, or nothing, and then ^C.

Now you will be back at the LOCK _ prompt from which you can exit by typing Q. Log out ($$U), and wait for the message SHUTDOWN COMPLETE. You should now be talking to non-timesharing DDT. Now you can power down the PDP-10, or go back to DSKDMP with $U.