This article is rated C-class on Wikipedia's
content assessment scale. It is of interest to the following WikiProjects: | ||||||||||||||
|
This article is or was the subject of a Wiki Education Foundation-supported course assignment. Further details are available on the course page. Student editor(s): Harshalgala, Darshanypatel.
Above undated message substituted from Template:Dashboard.wikiedu.org assignment by PrimeBOT ( talk) 09:50, 17 January 2022 (UTC)
Here's something I posted to the TUHS list last November (2015) that you might enjoy:
Since you asked, here's the true story of how I came up with the delta encoding, a story never before told.
I was living in a garden apartment in Sayreville, NJ, and at night would walk my girlfriend's dog along a hillside just outside our front door. It was usually cold, I didn't like the dog (still don't like dogs), and hated dodging the piles of dog shit while he tugged on the leash. So, as a coping mechanism, I used to let my mind wander, and one evening it was wandering and wondering about a problem I was struggling with, which was how to store the source and the deltas all in the same file. (It was a "data set," on the IBM OS/360 system we were using--we weren't on UNIX yet.)
Anyway, no doubt simultaneously with this unpleasant animal taking a shit, I came up with idea of surrounding pieces of text with markers. (The algorithm itself is documented in my original 1975 paper, which you can read about here: http://basepath.com/aup/talks/SCCS-Slideshow.pdf.)
(Wouldn't this be an even better story if I said that the little piles of dog poop on the hillside looked like markers in the soft glow of a full moon? It's not true, but perhaps I'll tell it that way if the occasion arises in the future.)
When I got inside, I started to sketch out how the markers might work, and came up with interesting observation that insertion start/end markers obviously nested, but deletion start/end markers did not nest with insert start/end markers. This is obvious if you think about it the right way: When you delete, the text you're deleting could have been added at various times, but when you insert, the inserted text is always added at the same time.
I didn't have replacement markers; insert and delete were enough, I thought.
I kept fooling around with the idea until I had an algorithm that I thought would work to retrieve any version with a single pass. (It's in the paper, referenced above.)
To prove the algorithm to be correct, I enumerated all possible cases of insertions mixed in with deletions. I don't recall how many cases I had, but I think it was around 20 or 30. Then I painstakingly went though every case, making sure the algorithm produced the right answer. This was a rare example of me doing actual work.
Coding it up, as I remember, was very easy, as the scheme is pretty simple. I'm sure I had it running in SNOBOL4 in a day or two. Redesigning SCCS in C for UNIX came maybe a year or so later, but the algorithm remained the same.
Larry [McVoy] very kindly says: "SCCS has interleaved deltas. It's a brilliant design that has far far better performance than anything else out there."
Maybe it was brilliant, but I can tell you that I was just trying to pass the time while that stupid dog did his business.
Rochkind ( talk) 05:12, 18 February 2016 (UTC)
Sure. It's in the public domain. Referencing my website (basepath.com) would be nice. Rochkind ( talk) 14:28, 18 February 2016 (UTC)
Can anyone tell me why the page says "Operating system Unix-like, Windows" in the box at upper right? Clearly SCCS is part of the UNIX world. A Windows port might be possible, and might even exist, but it's misleading to refer to SCCS as a Windows application. Rochkind ( talk) 04:52, 18 February 2016 (UTC)
My understanding of Cygwin is that it's a virtual UNIX environment. How is that a port? Rochkind ( talk) 14:30, 18 February 2016 (UTC)
Why were my links to Marc Rochkind's web log deleted? The note says they are "vanity links", but the log entry discusses Marc's recollections of creating SCCS. I think they are relevant to this article and I would like to see them included. —The preceding unsigned comment was added by Seitz ( talk • contribs) .
I removed the final paragraph of the main article which discussed the inclusion of SCCS in the Single UNIX Specification. I did so for two reasons:
Hi.. Anyone knows if there is a freeware or shareware which provides a windows based GUI for SCCS repositories?
Prasad RA HCL Technologies Bangalore
ClearCase, PVCS, and Visual SourceSafe were recently added as systems using the SCCS file format. This was the first I'd heard of that. Does someone have a source to verify this? -- Seitz 04:06, 5 June 2006 (UTC)
-- ClearCase uses an interleaving branching structure like SCCS, but it doesn't use SCCS format, and for very good reason: SCCS only supports a single branch off of the trunk. You can't have a branch off of a branch. (You can, but SCCS's file format doesn't directly support it). The interleaving branch method used by SCCS has an advantage over RCS's format in that it can pull up almost any version just as quickly while RCS's format can pull up the latest version very quickly, but takes longer and longer the more versions it has to go back.
I suspect that PVCS might use SCCS format because it was originally a front end for SCCS. Sablime (another AT&T product) does use SCCS format.
Addendum: I just confirmed that ClearCase definitely does not use SCCS format. I've also found the script pcvs_to_rcs script which is different from the sccs2rcs script that comes with CVS. This pretty much confirms that PCVS doesn't use SCCS format.
I can't vouch for SourceSafe (although I have my doubts since it uses a proprietary database to store its source code) and TeamWare. It is pretty much well known that Bitkeeper uses SCCS format. I'll also add Sublime.
I removed ClearCase and PVCS from the list of version control systems that use SCCS format:
David W.
I happened to recall that UNIVAC EXEC 8 had versioned files, which could predate SCCS. The feature was accessed by the "elt" processor, which could store up to 63 versions in an element (and wrap around when there were more). EXEC 8 was released in 1964. I don't see a source which backs up the comment that SCCS was the first such system. Tedickey ( talk) 10:50, 7 April 2010 (UTC)
That's true--Exec 8 did have versioned files--but it wasn't a revision control system. And, of course, since the earliest days of computing, programmers always kept past versions of their code. Rochkind ( talk) 23:22, 6 March 2011 (UTC)
It would be nice if there were a better source for the injected opinion than an obscure (and inaccessible), uncited paper whose purpose was to advertise yet another program. TEDickey ( talk) 23:15, 6 June 2011 (UTC)
As far as I can tell, there is an official SCCS included with UNIX, which is not the same as the version linked here by User:Schily. In my opinion, his version should be considered a fork, and the software infobox should refer to the original UNIX version, despite it not being actively developed anymore. -- 138.246.2.113 ( talk) 09:06, 12 July 2011 (UTC)
The statement above by talk, "any SCCS version from any UNIX vendor must be seen as a private fork" is, I believe, accurate. Certainly the vendors' SCCS versions differ in ways not easily explainable by any mechanism apart from a sequence of forks. Some of the differences between vendors' versions are described at http://www.gnu.org/software/cssc/manual/SCCS-Version-Differences.html JamesYoungman ( talk) 22:19, 30 June 2014 (UTC)
There have been attempts from IP 138.246.2.113 to introduce false claims on licensing.
SCCS was closed source until December 19 2006. At that time, SCCS was released under the Common Development and Distribution License by Sun Microsystems.
If SCO was not bought by Caldera Linux, SCCS would have been released under the BSD license in 2001, but this did not happen.
SCCS is part of PWB and SCCS sources are definitely not part of the UNIX sources even though often kept in a single directory tree. SCCS sources have been put on the CSRG CDs that contain the BSD UNIX SCCS history between 1978 and 1994. The code on these CDs is however not OpenSource and the SCCS sources that can be seen in various FreeBSD CVS repositories cannot be distributed legally to people that do not own a related AT&T source code license.
The only legally distributable SCCS source code is the one that is based on the code that has been made available by Sun in December 2006. -- Schily ( talk) 09:28, 13 July 2011 (UTC)
Please remove such markers only if you found a suitable source to quote!
The current SCCS development on sccs.berlios.de fixed many problems that are still present in "vendors" SCCS versions. If there was active development at the side of the UNIX vendors, these vendors did of course fix their problems... -- Schily ( talk) 15:22, 30 July 2011 (UTC)
Reading the thread on the discussion, it's apparent that there was little interest on Sun's part in making SCCS free, that (lacking a better source than those given), that it was figuratively tossed into the box simply as an afterthought. TEDickey ( talk) 12:07, 10 November 2011 (UTC)
Jörg's version is based on the Solaris fork of SCCS, IBM ships an own fork of SCCS, HP does and SCO does. If you believe that the term fork is appropriate, it is of course also appropriate and needed for various UNIX vendor's versions. Please do not add discrediting terms to wikipedia and treat comparable versions equal. — Preceding unsigned comment added by 130.149.17.4 ( talk) 12:31, 17 November 2011 (UTC)
Editor's change comment asserts that SCCS was "dominant" until "1990". That comment is unsourced. Most sources agree that SCCS was supplanted by RCS and/or CVS, though the timescale for this is vague. The sentence should be amended to reflect available WP:RS, rather than simply removing it. TEDickey ( talk) 10:56, 22 March 2012 (UTC)
Probably no one except for the 2-3 individuals with a personal interest in it would disagree. For example
(before getting into a long discussion, check on the definition of "obsolete") TEDickey ( talk) 23:03, 5 May 2014 (UTC)
Claiming that something that is part of a recent standard (POSIX) is obsolete sounds a bit stange. Schily ( talk) 10:15, 6 May 2014 (UTC)
TEDickey ( talk) 23:56, 6 May 2014 (UTC)
Do I get a vote on this? It is more than obvious that SCCS is completely obsolete. But it is great that people are still arguing about something I did as a 24-year-old kid almost two generations ago. Beat that with a stick! Rochkind ( talk) 05:00, 18 February 2016 (UTC)
Obsolete doesn't mean dead and unused. Many photographers shoot with a Nikon F, but it's obsolete. Really, if you asked a random sample of twenty-something programmers what they used, about 95% of them would say GitHub, the others would name some other cloud-based system, and only those paying attention in their software engineering classes would even know what SCCS was. Rochkind ( talk) 14:34, 18 February 2016 (UTC)
SCC compliant and 'SCC' evokes 'SCCS' and the ability to make sources interchangeable among different vendors. This was a non trival problem at one time (when 'BUNCH', 'mainframe', and 'mini' meant state-of-the-art). Even Microsoft thought so, as late as 1989. I would think have thought that citations like the ones just reverted make a difference to the article. Apparently not. -- Ancheta Wis (talk | contribs) 14:57, 14 February 2015 (UTC)
Usually, edits that address inline tags are considered helpful. But it appears that their removal are collateral damage from interchanges between parties with a long history. I would like to do what I can to minimize this sort of damage, as it factionalizes the encyclopedia, which is not helpful to it. Any suggestions? -- Ancheta Wis (talk | contribs) 15:14, 14 February 2015 (UTC)
Two obvious problems with that as a source: (a) it was written in 1997, and (2) it was not written as a neutral survey of the state of the art, but rather to promote a different tool. TEDickey ( talk) 19:41, 10 September 2016 (UTC)
Likewise, the suggested links for BitMover and Teamware date from the later 1990s. Neither supports the statement to which they were added TEDickey ( talk) 21:33, 10 September 2016 (UTC)
It strikes me ( 212.44.43.190 ( talk) 22:35, 27 January 2017 (UTC)) that this section is missing the sccs delta command to actually commit the change to the checked out file. Retrieving the file with sccs edit is moderately pointless unless you check the change back in. sccs sccsdiff is also somewhat interesting to the user, but not obviously missing.
The referenced paper does not actually say SCCS was initially released in 1972. It says "... when we began development of it (in late 1972)" and "The first release of SCCS was coded, debugged, and tested by one person in less than three months." and goes on to say that there was a six-month trial after completing the prototype. That would make the initial release in 1973 (agreeing with a later comment about 1973). The paper does not identify the actual developer of this initial version, but in the acknowledgments section cites three different developers who "worked with the author on the design and coding" TEDickey ( talk) 22:43, 9 September 2019 (UTC)
Right -- initial release was in 1973. Entirely coded by me; other cited contributors did not do any development or coding of SCCS. One of them, as I recall, did some coding on a related utility. Rochkind ( talk) 21:12, 12 August 2020 (UTC)
The given source does not say that. Rather, it indicates that Rochkind developed a prototype (e.,. proof of concept) and was able to get one moderately large group (one group of 100 developers out of several tens of thousands at that point in time) to use it for some trial period. The previous revision wasn't so blatantly promotional. TEDickey ( talk) 21:04, 7 May 2020 (UTC)
"100 developers out of several tens of thousands" isn't really right. Much less than a thousand worked at the location where the first version was put on the mainframe (Piscataway, NJ). That version was never packaged up for distribution or installation. The developers simply used it on the same mainframe on which it was developed. Rochkind ( talk) 21:19, 12 August 2020 (UTC)
I can't find anythign related to SCCS on this website. It would make much more sense to link to http://sccs.sourceforge.net/ , maybe not as an official repository, but it is probably the best available now. 93.254.27.45 ( talk) 08:36, 10 June 2022 (UTC)
Here's one of the mentions: sccs - front end for the SCCS subsystem (DEVELOPMENT) TEDickey ( talk) 10:55, 10 June 2022 (UTC)
This article is rated C-class on Wikipedia's
content assessment scale. It is of interest to the following WikiProjects: | ||||||||||||||
|
This article is or was the subject of a Wiki Education Foundation-supported course assignment. Further details are available on the course page. Student editor(s): Harshalgala, Darshanypatel.
Above undated message substituted from Template:Dashboard.wikiedu.org assignment by PrimeBOT ( talk) 09:50, 17 January 2022 (UTC)
Here's something I posted to the TUHS list last November (2015) that you might enjoy:
Since you asked, here's the true story of how I came up with the delta encoding, a story never before told.
I was living in a garden apartment in Sayreville, NJ, and at night would walk my girlfriend's dog along a hillside just outside our front door. It was usually cold, I didn't like the dog (still don't like dogs), and hated dodging the piles of dog shit while he tugged on the leash. So, as a coping mechanism, I used to let my mind wander, and one evening it was wandering and wondering about a problem I was struggling with, which was how to store the source and the deltas all in the same file. (It was a "data set," on the IBM OS/360 system we were using--we weren't on UNIX yet.)
Anyway, no doubt simultaneously with this unpleasant animal taking a shit, I came up with idea of surrounding pieces of text with markers. (The algorithm itself is documented in my original 1975 paper, which you can read about here: http://basepath.com/aup/talks/SCCS-Slideshow.pdf.)
(Wouldn't this be an even better story if I said that the little piles of dog poop on the hillside looked like markers in the soft glow of a full moon? It's not true, but perhaps I'll tell it that way if the occasion arises in the future.)
When I got inside, I started to sketch out how the markers might work, and came up with interesting observation that insertion start/end markers obviously nested, but deletion start/end markers did not nest with insert start/end markers. This is obvious if you think about it the right way: When you delete, the text you're deleting could have been added at various times, but when you insert, the inserted text is always added at the same time.
I didn't have replacement markers; insert and delete were enough, I thought.
I kept fooling around with the idea until I had an algorithm that I thought would work to retrieve any version with a single pass. (It's in the paper, referenced above.)
To prove the algorithm to be correct, I enumerated all possible cases of insertions mixed in with deletions. I don't recall how many cases I had, but I think it was around 20 or 30. Then I painstakingly went though every case, making sure the algorithm produced the right answer. This was a rare example of me doing actual work.
Coding it up, as I remember, was very easy, as the scheme is pretty simple. I'm sure I had it running in SNOBOL4 in a day or two. Redesigning SCCS in C for UNIX came maybe a year or so later, but the algorithm remained the same.
Larry [McVoy] very kindly says: "SCCS has interleaved deltas. It's a brilliant design that has far far better performance than anything else out there."
Maybe it was brilliant, but I can tell you that I was just trying to pass the time while that stupid dog did his business.
Rochkind ( talk) 05:12, 18 February 2016 (UTC)
Sure. It's in the public domain. Referencing my website (basepath.com) would be nice. Rochkind ( talk) 14:28, 18 February 2016 (UTC)
Can anyone tell me why the page says "Operating system Unix-like, Windows" in the box at upper right? Clearly SCCS is part of the UNIX world. A Windows port might be possible, and might even exist, but it's misleading to refer to SCCS as a Windows application. Rochkind ( talk) 04:52, 18 February 2016 (UTC)
My understanding of Cygwin is that it's a virtual UNIX environment. How is that a port? Rochkind ( talk) 14:30, 18 February 2016 (UTC)
Why were my links to Marc Rochkind's web log deleted? The note says they are "vanity links", but the log entry discusses Marc's recollections of creating SCCS. I think they are relevant to this article and I would like to see them included. —The preceding unsigned comment was added by Seitz ( talk • contribs) .
I removed the final paragraph of the main article which discussed the inclusion of SCCS in the Single UNIX Specification. I did so for two reasons:
Hi.. Anyone knows if there is a freeware or shareware which provides a windows based GUI for SCCS repositories?
Prasad RA HCL Technologies Bangalore
ClearCase, PVCS, and Visual SourceSafe were recently added as systems using the SCCS file format. This was the first I'd heard of that. Does someone have a source to verify this? -- Seitz 04:06, 5 June 2006 (UTC)
-- ClearCase uses an interleaving branching structure like SCCS, but it doesn't use SCCS format, and for very good reason: SCCS only supports a single branch off of the trunk. You can't have a branch off of a branch. (You can, but SCCS's file format doesn't directly support it). The interleaving branch method used by SCCS has an advantage over RCS's format in that it can pull up almost any version just as quickly while RCS's format can pull up the latest version very quickly, but takes longer and longer the more versions it has to go back.
I suspect that PVCS might use SCCS format because it was originally a front end for SCCS. Sablime (another AT&T product) does use SCCS format.
Addendum: I just confirmed that ClearCase definitely does not use SCCS format. I've also found the script pcvs_to_rcs script which is different from the sccs2rcs script that comes with CVS. This pretty much confirms that PCVS doesn't use SCCS format.
I can't vouch for SourceSafe (although I have my doubts since it uses a proprietary database to store its source code) and TeamWare. It is pretty much well known that Bitkeeper uses SCCS format. I'll also add Sublime.
I removed ClearCase and PVCS from the list of version control systems that use SCCS format:
David W.
I happened to recall that UNIVAC EXEC 8 had versioned files, which could predate SCCS. The feature was accessed by the "elt" processor, which could store up to 63 versions in an element (and wrap around when there were more). EXEC 8 was released in 1964. I don't see a source which backs up the comment that SCCS was the first such system. Tedickey ( talk) 10:50, 7 April 2010 (UTC)
That's true--Exec 8 did have versioned files--but it wasn't a revision control system. And, of course, since the earliest days of computing, programmers always kept past versions of their code. Rochkind ( talk) 23:22, 6 March 2011 (UTC)
It would be nice if there were a better source for the injected opinion than an obscure (and inaccessible), uncited paper whose purpose was to advertise yet another program. TEDickey ( talk) 23:15, 6 June 2011 (UTC)
As far as I can tell, there is an official SCCS included with UNIX, which is not the same as the version linked here by User:Schily. In my opinion, his version should be considered a fork, and the software infobox should refer to the original UNIX version, despite it not being actively developed anymore. -- 138.246.2.113 ( talk) 09:06, 12 July 2011 (UTC)
The statement above by talk, "any SCCS version from any UNIX vendor must be seen as a private fork" is, I believe, accurate. Certainly the vendors' SCCS versions differ in ways not easily explainable by any mechanism apart from a sequence of forks. Some of the differences between vendors' versions are described at http://www.gnu.org/software/cssc/manual/SCCS-Version-Differences.html JamesYoungman ( talk) 22:19, 30 June 2014 (UTC)
There have been attempts from IP 138.246.2.113 to introduce false claims on licensing.
SCCS was closed source until December 19 2006. At that time, SCCS was released under the Common Development and Distribution License by Sun Microsystems.
If SCO was not bought by Caldera Linux, SCCS would have been released under the BSD license in 2001, but this did not happen.
SCCS is part of PWB and SCCS sources are definitely not part of the UNIX sources even though often kept in a single directory tree. SCCS sources have been put on the CSRG CDs that contain the BSD UNIX SCCS history between 1978 and 1994. The code on these CDs is however not OpenSource and the SCCS sources that can be seen in various FreeBSD CVS repositories cannot be distributed legally to people that do not own a related AT&T source code license.
The only legally distributable SCCS source code is the one that is based on the code that has been made available by Sun in December 2006. -- Schily ( talk) 09:28, 13 July 2011 (UTC)
Please remove such markers only if you found a suitable source to quote!
The current SCCS development on sccs.berlios.de fixed many problems that are still present in "vendors" SCCS versions. If there was active development at the side of the UNIX vendors, these vendors did of course fix their problems... -- Schily ( talk) 15:22, 30 July 2011 (UTC)
Reading the thread on the discussion, it's apparent that there was little interest on Sun's part in making SCCS free, that (lacking a better source than those given), that it was figuratively tossed into the box simply as an afterthought. TEDickey ( talk) 12:07, 10 November 2011 (UTC)
Jörg's version is based on the Solaris fork of SCCS, IBM ships an own fork of SCCS, HP does and SCO does. If you believe that the term fork is appropriate, it is of course also appropriate and needed for various UNIX vendor's versions. Please do not add discrediting terms to wikipedia and treat comparable versions equal. — Preceding unsigned comment added by 130.149.17.4 ( talk) 12:31, 17 November 2011 (UTC)
Editor's change comment asserts that SCCS was "dominant" until "1990". That comment is unsourced. Most sources agree that SCCS was supplanted by RCS and/or CVS, though the timescale for this is vague. The sentence should be amended to reflect available WP:RS, rather than simply removing it. TEDickey ( talk) 10:56, 22 March 2012 (UTC)
Probably no one except for the 2-3 individuals with a personal interest in it would disagree. For example
(before getting into a long discussion, check on the definition of "obsolete") TEDickey ( talk) 23:03, 5 May 2014 (UTC)
Claiming that something that is part of a recent standard (POSIX) is obsolete sounds a bit stange. Schily ( talk) 10:15, 6 May 2014 (UTC)
TEDickey ( talk) 23:56, 6 May 2014 (UTC)
Do I get a vote on this? It is more than obvious that SCCS is completely obsolete. But it is great that people are still arguing about something I did as a 24-year-old kid almost two generations ago. Beat that with a stick! Rochkind ( talk) 05:00, 18 February 2016 (UTC)
Obsolete doesn't mean dead and unused. Many photographers shoot with a Nikon F, but it's obsolete. Really, if you asked a random sample of twenty-something programmers what they used, about 95% of them would say GitHub, the others would name some other cloud-based system, and only those paying attention in their software engineering classes would even know what SCCS was. Rochkind ( talk) 14:34, 18 February 2016 (UTC)
SCC compliant and 'SCC' evokes 'SCCS' and the ability to make sources interchangeable among different vendors. This was a non trival problem at one time (when 'BUNCH', 'mainframe', and 'mini' meant state-of-the-art). Even Microsoft thought so, as late as 1989. I would think have thought that citations like the ones just reverted make a difference to the article. Apparently not. -- Ancheta Wis (talk | contribs) 14:57, 14 February 2015 (UTC)
Usually, edits that address inline tags are considered helpful. But it appears that their removal are collateral damage from interchanges between parties with a long history. I would like to do what I can to minimize this sort of damage, as it factionalizes the encyclopedia, which is not helpful to it. Any suggestions? -- Ancheta Wis (talk | contribs) 15:14, 14 February 2015 (UTC)
Two obvious problems with that as a source: (a) it was written in 1997, and (2) it was not written as a neutral survey of the state of the art, but rather to promote a different tool. TEDickey ( talk) 19:41, 10 September 2016 (UTC)
Likewise, the suggested links for BitMover and Teamware date from the later 1990s. Neither supports the statement to which they were added TEDickey ( talk) 21:33, 10 September 2016 (UTC)
It strikes me ( 212.44.43.190 ( talk) 22:35, 27 January 2017 (UTC)) that this section is missing the sccs delta command to actually commit the change to the checked out file. Retrieving the file with sccs edit is moderately pointless unless you check the change back in. sccs sccsdiff is also somewhat interesting to the user, but not obviously missing.
The referenced paper does not actually say SCCS was initially released in 1972. It says "... when we began development of it (in late 1972)" and "The first release of SCCS was coded, debugged, and tested by one person in less than three months." and goes on to say that there was a six-month trial after completing the prototype. That would make the initial release in 1973 (agreeing with a later comment about 1973). The paper does not identify the actual developer of this initial version, but in the acknowledgments section cites three different developers who "worked with the author on the design and coding" TEDickey ( talk) 22:43, 9 September 2019 (UTC)
Right -- initial release was in 1973. Entirely coded by me; other cited contributors did not do any development or coding of SCCS. One of them, as I recall, did some coding on a related utility. Rochkind ( talk) 21:12, 12 August 2020 (UTC)
The given source does not say that. Rather, it indicates that Rochkind developed a prototype (e.,. proof of concept) and was able to get one moderately large group (one group of 100 developers out of several tens of thousands at that point in time) to use it for some trial period. The previous revision wasn't so blatantly promotional. TEDickey ( talk) 21:04, 7 May 2020 (UTC)
"100 developers out of several tens of thousands" isn't really right. Much less than a thousand worked at the location where the first version was put on the mainframe (Piscataway, NJ). That version was never packaged up for distribution or installation. The developers simply used it on the same mainframe on which it was developed. Rochkind ( talk) 21:19, 12 August 2020 (UTC)
I can't find anythign related to SCCS on this website. It would make much more sense to link to http://sccs.sourceforge.net/ , maybe not as an official repository, but it is probably the best available now. 93.254.27.45 ( talk) 08:36, 10 June 2022 (UTC)
Here's one of the mentions: sccs - front end for the SCCS subsystem (DEVELOPMENT) TEDickey ( talk) 10:55, 10 June 2022 (UTC)