I've rehashed this here before... I'd really like to put this to bed (Dioxides Spinellis -- it would be great if you could put this some where in you files so it does not get lost).
I'll restate the history of fsck for my friend and one time lab partner, Ted Kowalski - aka research!frodo or frodo@ece.cmu.edu as Ted passed a few years ago and can not do this for himself.
Ted did his undergrad at Michigan and was Bill Joy's housemate (where wnj was also an undergrad) in the early 1970s. Both were MTS/360 hackers and were introduced to UNIX there. Ted would go to CMU for his grad work in the mid/late 1970s (where I knew him when I was there) and Joy would do his grad work at UCB in the same time frame (as did I were I knew him). I was originally a CMU TSS/360 [MTS's older brother] hacker and was introduced to UNIX by Ted.***
The original FS tools for UNIX icheck/dcheck/ncheck were very crude. TSS and MTS (used a similar/same FS format) and and had a similar program in the key of fsck that Ted was familiar (as did a number of DEC systems for that matter). Ted wrote the original version of premordial fsck for v6 at UMich (maybe v5 - Joy probably would know what the version of UNIX was there then).
Ted took "pre-fsck" to Bell Lab the summer between Mich and CMU. Ted would rewrite and "continue hacking" fsck at CMU in the next year targeting V6. It was at this time that CMU was switching from V5 to V6, I do not believe (remember) that Ted ever had fsck running on a V5 format FS, but early versions could definitely be compiled for either v6 or v7 with #ifdefs (I'm likely to have those sources somewhere if I can read a tape -- but I can tell you the bits were not in SCCS control). I remember taking his ire when we both edited a file at the same time ;-)
BTW: the reason why the errors from the original version of fsck were all in UPPER CASE was because that's TSS and MTS did that. So that's how I was taught for sure and I believe Ted also. A number of early CMU UNIX programs look this way.
Note: Ted was originally in the "UNIX Support Group" @ BTL - aka USG (summit, not research and IIRC was Armando's officemate at USG). By the early 1980s, Ted would become part of Research, so the research!frodo moniker became his (although I can not state when that was but other might know).
When Ted (and Armando) were part of USB ???1977 or 78 maybe?? working on a kernel referred to as UNIX/TS - which would later become the kernel release by USG in PWB 2.0. UNIX/TS was loosely based on bits that Ken and Dennis were working with in Murray Hill - but the kernel and FS difference between v6 and v7 were in UNIX/TS (PWB 2.0 et els).
At some point (June I think) Dennis (and the research folks) took a snap shot of what was the research in 1979. This would be released the folks outside of BTL as V7. Ted had not yet completed fsck and so it was not (yet) in the research system (i.e. they still used icheck/ncheck/dcheck). But Ted would later put it into what would become PWB 2.0.
Similarly, Ted would also give copies of the CMU program to Ken/Dennis, Bill, and Armando for sure and I suspect some of his other friends at UMich had it also. I had done some >>small<< things to help him with the program during my CMU time so I had it (it was how I learned C after being an assembler, Bliss, Algol and SAIL hacker from the TSS, 10s and VMS).
Those of us UNIX hackers from CMU are also likely to have had fsck such as dvk (CS), gss (BIO), tron(Mellon), and others (for instance, I believe Wayne Gramlich who was gss's housemate in Pittsburgh brought fsck from CMU to MIT when he moved from undergrad @ CMU to grad student at MIT - again someone like Noah might know when it showed up there).
The point is that fsck was officially a "CMU/EE Dept developed program" - although frodo certainly used UMich, as well as AT&T resources at USG hacking on it also. But because of the CMU origins it was able to swim the UNIX oceans independently of the AT&T distribution methods of either research or summit. For instance, I brought it to Tektronix before I was at UCB and it was at UCB by the time I was there.
I suspect it was Joy who put it into BSD at some point, although there was definitely a number of students and faculty starting with Ken that moved between BTL and UCB (i.e. any BTL "OYOC" student could have brought anything with them); much less common students between CMU/UCB such as myself, Mike Carey, Shafi Goldwasser just in my class but as I said I think it predates us there. I would have expected fsck to become part of BSD around 3.0 but it might not have been until 4.0 or 4.1. Also any SCCS files you have from Joy/Kirk, are a number of years later than the original development. They are based on the version wnj would have gotten from Ted at some point.
How it made it to DEC, I do not know, although there were enough folks from lots of places like BTL much less academic institutions such as CMU (including Gordon Bell who was one of our Profs, Dave Roger's who ran the Vax project, Sam Fuller, and Bell's student Bell Strecker), that went to DEC that it's not surprising fsck made it there too.
Clem
***A side note, while Multics/CTSS impacted the BTL & MIT folks, and untold story of UNIX history is how TSS, MTS and VM/CMS for the IBM 360 had impact on many for the UNIX hackers of that same time from other academic centers (CMU, MIT, Stanford, Cornell, Princeton ...).