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* [TUHS] Unix v6 File System information
@ 2016-02-21 11:44 Noel Chiappa
  2016-02-21 13:34 ` Dave Horsfall
                   ` (3 more replies)
  0 siblings, 4 replies; 36+ messages in thread
From: Noel Chiappa @ 2016-02-21 11:44 UTC (permalink / raw)


    > From: Will Senn

    > Is there a good source of information about the Unix v6 filesystem 

http://minnie.tuhs.org/cgi-bin/utree.pl?file=V6/usr/man/man5/fs.5

    > Also, is there a source for the history of the early Unix filesystems
    > from v6 onward?

I don't know of one (although there is that article on the 4.2 filesystem),
but would love to hear of one.

I gather that V7 is basically V6 except the block numbers are 32 bits, not 16.

	Noel


^ permalink raw reply	[flat|nested] 36+ messages in thread
* [TUHS] Unix v6 File System information
@ 2016-02-22  1:54 Norman Wilson
  2016-02-22  3:02 ` Larry McVoy
  0 siblings, 1 reply; 36+ messages in thread
From: Norman Wilson @ 2016-02-22  1:54 UTC (permalink / raw)


Sometime back before the turn of the century, I remember
writing up a summary of the evolution of the UNIX file
system, starting with the earliest system I could find
information for (possibly the PDP-7 system) and running
through the printed manuals as things changed, up to
the Seventh Edition.

I think I've found it; I'll look it over and try to put
it somewhere on the web in the next day or two.

Norman Wilson
Toronto ON


^ permalink raw reply	[flat|nested] 36+ messages in thread
* [TUHS] Unix v6 File System information
@ 2016-02-21 21:51 Noel Chiappa
  0 siblings, 0 replies; 36+ messages in thread
From: Noel Chiappa @ 2016-02-21 21:51 UTC (permalink / raw)


    > From: Random832

    > That's the superblock. Look in ino.h.

Oh, right you are. Thanks for catching my mistake! (I don't have anything
like the same familiarity with V7 as I do with V6; never did any system
hacking on the former.)

Now that you mention it, I do seem to remember this kludge; IIRC, a later
Unix paper described the V7 inode layout. I never looked at the actual code,
though. Now that I do, it looks like iexpand() (in iget.c) is not exactly
portable! On a machine with a different byte order for the bytes within a
long, that ain't gonna work...

	Noel


^ permalink raw reply	[flat|nested] 36+ messages in thread
* [TUHS] Unix v6 File System information
@ 2016-02-21 18:27 Noel Chiappa
  2016-02-21 18:59 ` Clem Cole
  0 siblings, 1 reply; 36+ messages in thread
From: Noel Chiappa @ 2016-02-21 18:27 UTC (permalink / raw)


    > From: Will Senn

    > Thanks for the link.

Sure. It's worth reading the entire V6 manual if you're going to be doing a
lot with it - lots of goodies hidden in places like that. Also the two BSTJ
Unix issues. (I think they are available online, now.)

    > Supposing I created a byte faithful representation of a V6 filesystem
    > on my mac, would I then be able to load the file in simh as an RK05 and
    > mount and access its files and directories from a V6 instance? 

That's really a SIMH question, and I don't use SIMH; I use Ersatz11. That is
certainly how Ersatz11 works; I just FTP'd the RK05 distro images over, set
them up as the files that 'implemented' various RK05 drives, and (modulo a
few teething Ersatz11 configuration issues) away it went.

	Noel


^ permalink raw reply	[flat|nested] 36+ messages in thread
* [TUHS] Unix v6 File System information
@ 2016-02-21 17:50 Noel Chiappa
  2016-02-21 18:36 ` Random832
  2016-02-22 13:10 ` ron
  0 siblings, 2 replies; 36+ messages in thread
From: Noel Chiappa @ 2016-02-21 17:50 UTC (permalink / raw)


    > From: Random832 

    > They're 24 bits, aren't they?

Not according to the source:

	typedef	long		daddr_t;

	daddr_t	s_fsize;   	/* size in blocks of entire volume */
	short  	s_nfree;   	/* number of addresses in s_free */
	daddr_t	s_free[NICFREE];/* free block list */

(from param.h and filsys.h respectively).

    > From: Ron Natalie

    > The V6 block numbers were 24 bits.

Maybe you're thinking of the byte number within the file? The file length
was stored in an word plus a byte in the inode in V6:

	char	i_size0;
	char	*i_size1;  

but the block number in the device was a word:

	int	s_fsize;	/* size in blocks of entire volume */
	int	s_nfree;	/* number of in core free blocks (0-100) */
	int	s_free[100];	/* in core free blocks */

"Use the source, Luke!"

	Noel


^ permalink raw reply	[flat|nested] 36+ messages in thread
* [TUHS] Unix v6 File System information
@ 2016-02-21  9:45 Will Senn
  2016-02-21 10:01 ` Dave Horsfall
  2016-02-21 10:27 ` arnold
  0 siblings, 2 replies; 36+ messages in thread
From: Will Senn @ 2016-02-21  9:45 UTC (permalink / raw)


All,

Is there a good source of information about the Unix v6 filesystem 
outside of the source code itself? Also, is there a source for the 
history of the early Unix filesystems from v6 onward?

Thanks,

Will


^ permalink raw reply	[flat|nested] 36+ messages in thread

end of thread, other threads:[~2016-03-10  9:31 UTC | newest]

Thread overview: 36+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2016-02-21 11:44 [TUHS] Unix v6 File System information Noel Chiappa
2016-02-21 13:34 ` Dave Horsfall
2016-02-21 15:21   ` Will Senn
2016-02-21 17:21   ` John Cowan
2016-02-22  1:58     ` Dave Horsfall
2016-02-22  2:32       ` Lyndon Nerenberg
2016-02-22 12:30         ` Tony Finch
2016-02-21 15:36 ` Will Senn
2016-02-21 20:24   ` Warren Toomey
2016-02-21 17:31 ` Random832
2016-02-21 17:36 ` ron
  -- strict thread matches above, loose matches on Subject: below --
2016-02-22  1:54 Norman Wilson
2016-02-22  3:02 ` Larry McVoy
2016-02-21 21:51 Noel Chiappa
2016-02-21 18:27 Noel Chiappa
2016-02-21 18:59 ` Clem Cole
2016-02-21 19:31   ` arnold
2016-02-21 20:45     ` Will Senn
2016-02-21 21:06       ` Clem Cole
2016-02-21 21:05   ` Will Senn
2016-02-21 21:21     ` Clem Cole
2016-02-22  2:20     ` Warren Toomey
     [not found]       ` <2D41A491-40CD-41DB-B3BA-0ACBD831E2C7@gmail.com>
2016-02-22  7:27         ` Warren Toomey
2016-02-21 17:50 Noel Chiappa
2016-02-21 18:36 ` Random832
2016-02-22 13:10 ` ron
2016-02-21  9:45 Will Senn
2016-02-21 10:01 ` Dave Horsfall
2016-03-04 19:10   ` Jacob Ritorto
2016-03-10  8:51     ` Dave Horsfall
2016-03-10  9:31       ` SPC
2016-02-21 10:27 ` arnold
2016-02-21 12:29   ` Dave Horsfall
2016-02-21 13:54     ` arnold
2016-02-21 14:40       ` Clement T. Cole
2016-03-04  9:27       ` Dave Horsfall

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