On Fri, Feb 10, 2023 at 8:33 AM Dan Cross <crossd(a)gmail.com> wrote:
On Fri, Feb 10, 2023 at 10:26 AM Warner Losh
<imp(a)bsdimp.com> wrote:
On Fri, Feb 10, 2023, 3:12 AM Lars Brinkhoff
<lars(a)nocrew.org> wrote:
Jonathan Gray wrote:
Great, thanks!
It's a bit sad to read in supdup.mss "Unfortunately, very few machines
have TCP/Supdup servers. The only servers known to us are on Mit-MC and
Su-AI, and 4.2 Unix machines running a server we distribute." At this
point, three old ITS machines had recently fallen over, one after the
other, and MC was the only one left standing. But not long after, four
new ones would appear. One of which is still up and running!
I wonder if this was the same supdup that the early BSDs used to
distribute their
source in the 90s ..
I believe they are entirely different.
If I recall correctly (and it's been a while...) csup, CVSup, et al
were based on `sup`, which was a file distribution tool somewhat like
`rdist`, which came from CMU. csup/cvsup was optimized for moving
source code deltas (a la CVS repositories) around. I recall a
graphical client written in Modula-3?
cvsup was written by John Polstra in Modula-3. IT had an optional GUI
client.
It was notable at the time for using the radical new concept of threading to
stream the exchange elements of the protocol, speeding it up radically over
the old sup protocol, which was entirely synchronous. In addition, it knew
about the structure of RCS files, and exchanged only delta information so
could make a number of interesting optimizations in transmission of data
and delta data (since RCS had rules for the version number's forms, etc). It
was from the very early days of the FreeBSD project (somewhere between
FreeBSD 2.0 and 2.1) because the sup protocol was killing the wallnut creek
CD-ROM servers with its load (a primary motivation for teaching it about the
structure of RCS files).
csup was a later rewrite in 'c' as the module-3 compiler fell into
disrepair. It
was written by Maxime Henrion and is protocol compatible with the cvsup
programs. It lacked a gui, but was way more portable and didn't require that
a new architecture in FreeBSD first port the Module-3 compiler to it so
source
updates were possible (only slight exaggeration). cvsup was ported between
three or four different Modula-3 compilers as support for the language was
fading away....
Both became obsolete when the FreeBSD project moved to svn. It offered
not-quite-as-good, but good-enough delta updates, so cvsup and csup
became relegated to the dustbin of history.
The SUPDUP protocol used by ITS hosts was a
"Display Protocol" based
on TELNET:
https://www.rfc-editor.org/rfc/rfc734
I think the similarity in naming was just a coincidence.
Now that you say that, I recall that as well...
Warner