Talk:Time-sharing system evolution

Is MS Windows a timesharing system?
I've always thought a timesharing system had to support multiple concurrent users. AFAIK no Windows version does this - the NT-2000-XP-Vista lineage allows multiple logged-on users, but only 1 can use the system interactively at a time (I'm not sure about background tasks under multiple logged-on users). Philcha (talk) 20:41, 16 December 2007 (UTC)
 * Actually some Windows versions have supported this as far back as 1998, with Windows NT 4.0 Server, Terminal Server Edition. The current implementation is called Remote Desktop Services. But, MSDOS never provided any such thing. Snori (talk) 10:59, 1 June 2014 (UTC)

MS Windows other than 3
I think the table (which is an excellent summarising device) understates the complexity of the ancestry of Windows versions beyond Windows 3 (which was just a GUI front-end for MS-DOS):
 * Win NT was mainly influenced by OS2 and Vax VMS, and not significantly by Win 3 except that they support MS-DOS commands. Win 2000, Win XP and Win Vista are descendants of NT, with increasing imports of "user-friendliness" from the Win 95 lineage (earlier) and Mac OSs (recently).
 * I'm less sure about the main influences on Win 95, 98 and ME. They use much the same UI design and the same shortcut format (in the Start Menu, etc.) as the NT-2000-XP-Vista lineage, and like NT etc. support long filenames; but they resemble Win 3 in using a FAT-based file system and relying on co-operative multi-tasking because they lack pre-emptive multi-tasking.

The problem is how to express all this:
 * A full network of relationships / influences could be as confusing as a spider's web. It might help to colour-code the lines from each source / predecessor.
 * One could distinguish major and minor influences by the width of connecting lines in a network, but that would rather subjective. Philcha (talk) 20:37, 16 December 2007 (UTC)

Nonsense that has to go
I struggle to understand how any of these ever got into this article.

Programming languages: Yes, all these ran on time-sharing systems, but so did BASIC, umpteen editors and payroll programs etc.
 * APL
 * LISP
 * Smalltalk

Single task "OS"s: These couldn't run two apps at a time, let alone for remote users.
 * CP/M
 * MSDOS

Possible entries:
 * OS/2 (with the addition of Citrix MULTIUSER and Winview)
 * Microsoft Windows (but only from Windows NT 4.0 Terminal Server Edition)

I will remove them shortly unless anyone can provide a compelling argument against doing so. Snori (talk) 11:22, 1 June 2014 (UTC)
 * Done. I have left Windows and OS/2 for now, but will re-word in line with my comment above some time in the next few days. Snori (talk) 05:26, 4 June 2014 (UTC)
 * That just shows your ignorance. Read corresponding articles for that languages. They had early implementations which didn't depend on other OSes. In fact APL\360 was almost the first successful time-sharing option in time where IBM didn't offer any comparable alternative. And that implementation had very weak dependency on its host OS. Lisp machines even had their own hardware. These early systems influenced time-sharing development up to this day. 188.208.99.37 (talk) —Preceding undated comment added 11:16, 18 January 2019 (UTC)


 * Yes, I have the impression that APL\360 supported multiple users on multiple terminals on a single machine by doing its own time slicing, rather than by running multiple instances of the APL interpreter as ordinary programs atop a time-sharing OS. (Later versions may have left the time slicing/multi-user work up to the OS.)
 * What LISP systems did their own time-sharing in that fashion? As the edit comment for the edit that removed LISP from the list said, "Lisp machines were single user workstations, not time-sharing", and those systems weren't "early" in the history of time-sharing.
 * The same applies to Smalltalk. Guy Harris (talk) 17:20, 18 January 2019 (UTC)
 * Unfortunately, I'm not an expert on Lisp and Smalltalk. But I didn't rush to remove them either. OTOH, APL\360 source code is available at Computer History Museum and was fixed to run under Hercules emulator and OS/360, so it's known for sure that in order to do time-sharing it made invasive changes to its host OS which didn't provide any time-sharing on its own. I've restored APL with a cite to a paper which describes that period of history.188.208.99.37 (talk) 17:36, 18 January 2019 (UTC)

DTSS
DTSS was certainly not a DEC system as it ran on GE (later Honeywell) hardware.

I was not completely comfortable adding it to the MULTICS/UNIX section, but that seemed better than the alternatives. The DTSS and MULTICS projects overlapped. Doug McIlroy told me in an email thread, "Though the Multics team was well aware of DTSS, I can't think of any specific influence from DTSS." LCarl (talk) 14:38, 12 May 2019 (UTC)

LTSS/CTSS
I do not have access to reliable sources, but the Livermore Time Sharing Service (or System) probably should be included on this list. I believe it was written in a variant of Fortran. LTSS was a forerunner of the Cray Time Sharing System, an operating system used on some early Cray-1 systems. CTSS had a unique file deletion command, DESTROY. 207.231.0.246 (talk) 14:34, 5 July 2024 (UTC)