Talk:ITS 138

Interesting items in the ITS 1.4 manual

I saw a couple of interesting things in the ITS 1.4 manual. The first is that what we now call a 'process' is referred to in it as a "procedure". The manual will be a little bit more comprehensible if this is remembered! :-)

The second is something I caught in Section 5.1, right at the bottom of the page: "A procedure's core image may be easily swapped out without <blah, blah>". This was interesting because you had said that early ITS didn't do swapping? I looked for a while to see if I could find more on this 'swapping' (since they apparently had their own private language, and words might mean something else than they normally mean now :-), but all I could find quickly was in Section 6.1, at the bottom of page 56 (printed page number, not PDF): "while not in actual use they [separate copies of the command processor] could be swapped out of the system." On the other hand, in Section 1, on page 4, we find: "(2) All user programs reside in core storage ... (The coming installation of additional disk storage will enable the swapping of programs". Note that the term "program", not 'procedure' is used - do they mean something different, or had they changed their terminology, and this text in the Introduction wasn't caught, and updated? Similarly for the "will enable .. swapping": maybe this was added, and they just never went back to update this text? I have this vague memory that the very earliest system only had DECtapes, and no disks, so not swapping probably made sense there. I suppose you will have to study the code to see for certain! Jnc (talk) 12:56, 29 November 2023 (CET)