You're quite right, Tops-20 directory creation /is/ a pain in the neck
to the modern user.
However, a Tops-20 directory is a _very_ different beast than what you
would see in other operating systems.? It was a different time with
different costs.? Under DOS, Unix (all flavors), OS/2, Windows and IBM
z/OS (nee MVS) a directory is simply a place to put files.? So you say
make me a directory and /poof/, you're a directory.
Under Tops-20, directories have far richer semantics.? First of all,
they are the store of record for login credentials, which is quite
different from all the above and Tops-10, as well.? If you create a
directory--/anywhere/--and it is not FILES-ONLY and it has a password,
then you have just created a user. Furthermore connecting to a directory
is in no way like doing a CD.? Once you are connected, you have the same
rights as the owner and can use these rights to access files in other
directories that the owner has rights to.? Group management is superior
to Unix in that a directory can both be in multiple groups and provide
multiple groups.? It allows for far greater granularity.? Disk usage is
carefully kept track of.? However, management of all of it requires
special administrative capabilities to be given.
All of this was necessary in the days of machines have 10's of thousands
of users with strapped storage; I believe the default at Columbia for
undergraduates was 100 pages (about 350 KB) permanent storage and 1,000
working.? You've got to do things like that when all you can squeeze
into the machine room is a couple of gigabytes worth of disk drives.?
The careful group management was necessary to keep the more inquisitive
students from interfering with others' activities.? We needed special
programs to manage all the accounts, the groups and the storage.? Most
sites had home grown software like this and Columbia's was pretty nifty.
The only thing lacking was the ability for a user to create their own
sub-directory.? I began looking at this by sketching out an IPCF% based
client server paradigm.? The user would run a client to create the
directory and then the server would do all the automatic nice things.?
It grew to be quite complex as it had to go recursive to grab storage
from superior directories' allocation and then it would have had to
interface into the group management system to request groups for the
user to access the subdirectories.? I gave up when the line was
cancelled and we went to Sun SPARC.
Non-DEC versions of Tops-20 (such as Stanford and PANDA) implement
something called super-domestic structures where the user can always
access their subdirectories.? A limited version of relative directory
naming (viz, ./., ../) was implemented, also.? Columbia's group
management software was intelligent and flexible enough that we never
needed to use the super-domestic code.
Structure (and tape) mounts are also a very different thing, but that's
another story.
Maybe I'll look at it again after I finish my DAP changes and the new
FTP server.
------------------------------------------------------------------------
On 2/26/20 8:15 AM, Keith Halewood wrote:
I managed to get the KLH10 emulator compiled and running the Panda
distribution of TOPS-20 under Raspbian on a Pi 4 without too much
trouble. Its ?dpni20? process has no trouble talking to a TAP device
which is bridged with eth0 and thence onto the mixed
in-memory/real-ethernet DECnet connection to the HECnet. Admittedly,
I?m not that familiar with TOPS-20 or the ?hardware? on which it runs.
My main interest was MDL at the time. It?s still running as WALACH on
the HECnet. My main ?take-away? from the experience was: ?HOW many
questions do I have to answer in order to create a directory on this
thing???
On the SIMH side of things, I?m a bit stuck getting TOPS-10 running
from the DO scripts from the URL?. [I appear to have misplaced this
bit of information]
Keith
*From:*owner-hecnet at Update.UU.SE [mailto:owner-hecnet at Update.UU.SE]
*On Behalf Of *Rob Jarratt
*Sent:* 26 February 2020 11:51
*To:* hecnet at Update.UU.SE
*Subject:* RE: [HECnet] Multinet alternatives ...
I can?t remember now what the problems were, but I think I had
problems getting Phase III running on SIMH with the KMC or KDP (or
whatever it was).
*From:*owner-hecnet at Update.UU.SE <mailto:owner-hecnet at Update.UU.SE>
<owner-hecnet at Update.UU.SE <mailto:owner-hecnet at Update.UU.SE>> *On
Behalf Of *Thomas DeBellis
*Sent:* 25 February 2020 20:14
*To:* hecnet at Update.UU.SE <mailto:hecnet at Update.UU.SE>
*Subject:* Re: [HECnet] Multinet alternatives ...
What issues had you encountered talking to Tops-20??
If you are using the SIMH emulator for a KS processor, then the latest
version of Tops-20 you can run is 4.2, which I believe will do Phase
III.? Since there was never any Ethernet adapter for the KS (it was a
massbus device), I believe you must speak DDCMP, which we used with
KMC's, which would do 56Kbs.? There was a slower adaptor for 9.6Kbs,
but the name escapes me at the moment.
I've had little trouble with Tops-20 V7 DECnet; that is, once I got it
to working.? When I was modifying FAL/DAP to accept anonymous
transfers, I and and others beat on it quite a lot to wring the bugs
out.? These regression tests were against another 20, RSX 11M+ (or
whatever MIM:: is running) and a couple of Vaxen.? The operating
system level code was robust; no crashes.
We found some interesting bugs; I think my favorite was RSX wanting
all capital letters for months and Tops-20 sending capitalized months,
so file dates got messed up.? There were others, but they took some
effort to remediate; so, not so favorite...
On 2/25/20 1:38 PM, Rob Jarratt wrote:
Mine has been built to be portable (it is in C). I have it running
on Windows, Debian and FreeBSD. I have not tried on VMS, but I did
do a partial port to VAXELN. I don?t foresee great difficulties
getting it to run on VMS. It looks like I may have done some
partial VMS work, but it has been a while since I looked. I could
look into reviving/continuing that if there is interest.
Mine won?t talk to TOPS10/20, yet. I started something on that too
if I remember correctly, I did build a DDCMP implementation which
I think partially worked. I think I foundered on just getting
DECnet running on TOPS20 on SIMH, I did some work with Mark
Pizzolato and Timothe Litt to build a KDP emulation, but I
struggled to keep up with them and gave up in the end. I am not
sure where that went.
I need a bit of time to work out what my status is I think as it
has been a while.
Regards
Rob
*From:*owner-hecnet at Update.UU.SE
<mailto:owner-hecnet at Update.UU.SE> <owner-hecnet at Update.UU.SE>
<mailto:owner-hecnet at Update.UU.SE> *On Behalf Of *Robert Armstrong
*Sent:* 25 February 2020 14:42
*To:* hecnet at Update.UU.SE <mailto:hecnet at Update.UU.SE>
*Subject:* [HECnet] Multinet alternatives ...
?? What are the alternatives for bridging DECnet systems across
the Internet that don?t require any special hardware and can be
self hosted on OpenVMS/VAX?
? I?m aware of Paul?s Python router, but I didn?t think it ran on
a VAX.? Am I wrong about that?? Is there a Python for
OpenVMS/VAX?? I believe there?s a port for AXP but I didn?t know
about one for VAX.
? And I saw Rob mentioned his user mode DECnet router.? Same
questions ? what environment does that require?? ?And I saw
mention it being both Multinet and simh DDCMp compatible ? will it
talk to a simh KS10/TOPS10/DMR ?
Bob