Saving UNIX from /dev/null

Warren Toomey
Email: wkt@cs.adfa.edu.au

Abstract:

I review the efforts being undertaken to preserve old versions of UNIX, to gather information needed to maintain these systems, and the progress to provide legal access to old UNIX source.

The Legacy of UNIX

• UNIX turns 30 years old at the end of 1999

• Its elegant design & the powerful paradigms given to it by its developers are a major factor in its success

• By 1973, UNIX had:
  • Multiple concurrent users with passwords
  • Multiple protected processes with swapping
  • Process signals
  • Pipes

  • Hierachical filesystem with mountpoints
  • User/group/other r/w/x file permissions
  • Hard links on files
  • Devices accessed as files

  • The C language
  • Kernel written in C: image size of 26 Kilobytes

  • File I/O: open(), close(), read(), write(), seek(), pipe()
  • Processes: fork(), exec(), wait(), exit()

• 35 of the 48 syscalls are still in existence today

Why Bother Preserving UNIX?

• UNIX is definitely part of computing history.

• UNIX's history is pretty well documented.

• There has been little effort to preserve the artifacts of UNIX.

• Why would anybody want to?
  • A personal interest in memorabilia.
  • Own old hardware which can run these systems: PDP-11, VAX etc.
  • A few people maintaining/improving old systems: 2.11BSD, Quasijarus.

The PDP UNIX Preservation Society

• PUPS is a loose affiliation of people involved in the preservation, maintenance and development of UNIX.

• Originally just for PDP-11 systems, now for all `old' UNIX systems.

• Our web page is at http://minnie.cs.adfa.edu.au/PUPS/. See also http://minnie.cs.adfa.edu.au/TUHS/

• We also have a mailing list, with over 150 subscribers. A quiet list.

• Mailing list used to announce additions to our archive, ask about UNIX history, help each other out with software/hardware questions.

The PUPS Archive

• This is a central part of PUPS: a repository of src, bins, apps, info & misc. stuff related to UNIX.

• Kept as a set of on-line files.

• Where data comes from tapes, we try to retain details of record structure, and transcribe handwritten labels.

• Usually, tape contents are copied & converted to `tar' format.

• Tapes come in as they are found; we are lucky to have found several computer `packrats' who kept old stuff.

• The PUPS Archive contains:

  Bell Labs UNIX:

  V5, V6, V7, V7 patches.

  USDL/USL:

  PWB/UNIX, Mini-UNIX, 32V, SysIII, SysV.

  CSRG:

  1BSD, all 2BSDs, 3BSD, all 4BSDs, Net/1, Net/2.

  DEC:

  V7M, Ultrix-11.

  Homegrown UNIX:

  AUSAM, other modified versions.

  Software:

  Several old USENIX tapes; the Software Tools.

  Bug Fixes:

  An archive of net.v7bugs. 2BSD and 4BSD bug fixes.

  Tools:

  Tools to deal with tapes, filesystems etc.

  Emulators:

  Several hardware emulators.

• Recently, we received source to a UNIX kernel dated January 1973. We have managed to get it to run on a real PDP-11/45.

Providing Access to UNIX Source

• A UNIX source license is still required to access the source code.

• `Untainted' systems (Linux, the free BSDs, Minix) don't, obviously.

• Getting a V7 license was impossible: you had to get a SysVR4.2 one. $$$

  
  

  
  

• The only other access was the newly-released Lions Commentary. The copyright only allows you to read the book.

• Steven Schultz & I began to lobby SCO for cheap licenses in 1996. Freely-available source was out of the question, said SCO.

• An on-line petition to SCO (with 350 signatures) helped to convince them of the interest in cheap licenses.

• With excellent support from Dion Johnson at SCO, `Ancient UNIX' licenses came out in March 1998.

• A license costs US$100, & covers V1-V7, 32V, and derived PDP-11 systems. 165 people have bought licenses so far.

• Covering 32V was critical: this allowed Kirk McKusick to sell a 4CD set of all BSD releases.

Distributing the PUPS Archive

• SCO doesn't distribute media with the license. PUPS does, instead.

• We have on-line access to the PUPS Archive, for UNIX license holders. Currently, over 100 people have access.

• We have a network of 19 volunteers who distribute the archive on CD-ROM or tape. This is done on a cost-recovery basis.

• So far, at least 40 CDs have been distributed.

Old Artwork

• We are also interested in any UNIX memorabilia, including artwork.

• Below is one of the oldest pieces of UNIX art, done by Phil Foglio in 1976.

  
  

  
  

• The original has gone to /dev/null. This comes from a photo of a t-shirt owned by Mike O'Brien.

Old Documentation

• All the research manual editions (V1 - V7) still exist.

• Dennis Ritchie has the V1 manual on his web page.

• Several PUPS members are scanning in and OCR'ing the paper manuals to recreate the on-line versions.

Newsletters

• UNIX user groups were vital in the early days, as AT&T provided no software support.

• The groups' newsletters are a mine of useful information.

• I am working with Dave Horsfall to try & scan in all the old AUUGNs, make a CD-ROM, and pass it on to AUUG for safe-keeping.

The UNIX Family Tree

• One other project is a UNIX family tree.

• Access to the original sources is useful here to track down relationships.

• An initial attempt is hopefully hanging up in the foyer.

• We need details of the commercial UNIX versions.

Conclusion

• Preserving UNIX is a pastime, like preserving old cars.

• It will one day be useful for computing historians and archaeologists.

• Since PUPS was formed in 1995, we have put together an impressive collection of UNIX material.

• We have a network of people with a large amount of old UNIX knowledge.

• Our greatest achievement is to make cheap UNIX source licenses available.

• Preservation is ongoing. We will start to work on systems from the 1980s and 1990s soon!

• Donations of UNIX material to our archive is most welcome.