A friend just sent me a pointer to this site, which appears not
to have been mentioned on this list before:
PDP 11/70 Emulator
http://skn.noip.me/pdp11/pdp11.html
The site lists these working guest O/Ses:
RL0 BSD 2.9
RL1 RSX 11M v3.2
RL2 RSTS/E v7.0
RL3 XXDP
RK0 Unix V5
RK1 RT11 v4.0
-------------------------------------------------------------------------------
- Nelson H. F. Beebe Tel: +1 801 581 5254 -
- University of Utah FAX: +1 801 581 4148 -
- Department of Mathematics, 110 LCB Internet e-mail: beebe(a)math.utah.edu -
- 155 S 1400 E RM 233 beebe(a)acm.org beebe(a)computer.org -
- Salt Lake City, UT 84112-0090, USA URL: http://www.math.utah.edu/~beebe/ -
-------------------------------------------------------------------------------
All, I've got the original PDP-7 cat working in my PDP-7 user-mode
simulator called "a7out". The cat.s source code and the a7out program are
in the Github repository in src/cmds and tools, respectively.
The repository is at https://github.com/DoctorWkt/pdp7-unix
The mailing list is at http://minnie.tuhs.org/pipermail/pdp7-unix/
I'm attaching the a.out assembly output as the as7 assembler in the
repository currently is not quite ready for cat.s.
To run the original cat, create a text file, e.g. echo hello > file1
$ ./a7out a.out file1
hello <- the output of the PDP-7 machine code
Cheers, Warren
P.S Thanks again to Norman for getting us the scans.
> Norman Wilson is going to try and get us some higher quality scans which
will help a great deal in deciphering some of the hard to read characters.
A second scan, high or low quality, is a tremendous help. Diffing them
is a really good way to spot trouble.
Doug
On Thu, Feb 25, 2016 at 01:43:03PM -0500, Robert Swierczek wrote:
> Do you know if anybody has taken up the challenge of transcribing and
> simulating the PDP-7 Unix source code you have uncovered in your
> post http://minnie.tuhs.org/pipermail/tuhs/2016-February/006622.html
> If not, I would love to get started on it as a project.
Hi Robert, yes there is a project underway to type it all in and bring it
up on SimH and hopefully on a real PDP-7. I've set up a mailing list for
the project, so let me know if you would like to join: I'll add you.
The repository is at https://github.com/DoctorWkt/pdp7-unix. I've started
on the S1 section (in scans/), and I've also started work on an assembler
and a user-mode simulator (in tools/)
Norman Wilson is going to try and get us some higher quality scans which
will help a great deal in deciphering some of the hard to read characters.
Cheers, Warren
> 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
> 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
On Sun, Feb 21, 2016 at 09:21:14PM -0600, Will Senn wrote:
> Thanks for the link. The tools look useful. But, they appear to be extract from tape rather than create tape utils? I am away from a computer but will try them out later to make sure.
No, my bad. I thought they would make tapes, but I read the Readme files
and it doesn't look so. You could modify the mkfs.c tool that I wrote at
https://github.com/DoctorWkt/unix-jun72/blob/master/tools/mkfs.c
to write V6 filesystems. It shouldn't be too hard.
Cheers, Warren
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
> 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
> 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
