UNIX on PDP 11/23s

[guy at rlgvax.UUCP]

>      Certain of the utility programs that are dependant on the filesystem
> layout have names that are different from V7. As an example, 'fsck' on V7
> expects V7 filesystems (not V6) and uses the kernel file '\unix' for info
> of the filesystems to be checked. The VENIX/11 version of this utility is
> called 'fcheck', and uses the kernel file '/venix'. I consider these minor
> variations on the utility names to be only a minor inconvienience. It does
> make it clear which utilities have been changed, however.

Actually, "fcheck" was a program that came with PWB/UNIX - a V6 descendant -
written by Hal Pierson, formerly of BTL and now of CCI Office Systems Group;
Ted Kowalski modified it for the V7 filesystem to make "fsck" (just wanted to
give credit where credit was due!).  "fsck" does some checks which "fcheck"
didn't do, so unless Venturcom put those checks into their "fcheck" it won't
quite catch as many problems as "fsck" does.  (Be warned; PWB/UNIX changed
the V6 file system not to support doubly-indirect blocks (which cut the
maximum file size to 1MB, a "feature" propagated in the V7-based USG versions
which enforce this by setting the file size limit to 1MB.  Bleah!), but
"fcheck" supports the original V6 file system.  If you try to use "fcheck" on
a system with 8 singly-indirect blocks, change it.)  Also, the "lost+found"
directory for putting orphaned file into was an "fsck" "innovation" (actually,
the DEC Files-11 equivalents of "fsck" have done it for ages).

The name of the kernel executable image changes every time somebody ports UNIX,
so that's par for the course (it's been called "/xenix", "/perpos", "/vmunix",
and probably at least 10 other things).

	Guy Harris
	{seismo,ihnp4,allegra}!rlgvax!guy