ORVYL and WYLBUR

ORVYL and WYLBUR
Company / developer Stanford University
Programmed in 360/370 Assembler
Working state Historic
Initial release 1967, 1968
Available language(s) English
Supported platforms IBM S/360, S/370, and successors
License OpenSource
Official website http://www.stanford.edu/dept/its/support/wylorv/
History of IBM mainframe
operating systems

On early mainframe computers:

On S/360 and successors:

ORVYL and WYLBUR are the names associated with the Stanford Timesharing System.[1][2] Initially developed in 1967-68 for the IBM S/360-67 mainframe computer, it was one of the first time-sharing systems to be made available for IBM computers.

Contents

Overview

The names ORVYL and WYLBUR are often used interchangeably, but:

WYLBUR is not a full standalone operating system in the mold of Dartmouth Time Sharing System (DTSS) or Unix. Instead it runs on top of the ORVYL time-sharing system or an IBM batch operating system (OS/360, SVS, MVS). It takes the form of an editor with a Remote Job Entry system and thus has much the same relationship to ORVYL or the IBM operating systems as Emacs does to Unix. For these reasons WYLBUR is often thought of as a text editor rather than a time-sharing system. However whereas Unix does not need Emacs to provide time-sharing services, IBM's operating systems originally needed WYLBUR. Later innovations such as IBM's Time Sharing Option (TSO) made WYLBUR less relevant for IBM users and gradually replaced it.

Use

ORVYL and WYLBUR were used at the Stanford Linear Accelerator Center (SLAC), the European Organization for Nuclear Research (CERN), the U.S. National Institutes of Health (NIH), and many other sites. Retired from most sites in the late 1990s owing to concerns about Y2K issues, they remained in use at NIH until December 2009.[4] ORVYL and WYLBUR are still available as open source from Stanford.[5] There are also proprietary versions such as SuperWilbur.

ORVYL and WYLBUR were much admired as shown by this excerpt from a 2004 article titled "Computing at CERN: the mainframe era":

[In 1976 the IBM S/370-168] also brought with it the MVS (Multiple Virtual Storage) operating system, with its pedantic Job Control Language, and it provided the opportunity for CERN to introduce WYLBUR, the well-loved, cleverly designed and friendly time-sharing system developed at SLAC, together with its beautifully handwritten and illustrated manual by John Ehrman. WYLBUR was a masterpiece of design, achieving miracles with little power (at the time) shared amongst many simultaneous users. It won friends with its accommodating character and began the exit of punch-card machinery as computer terminals were introduced across the lab.[6]

Advantages and disadvantages

ORVYL and WYLBUR first became available in 1967-68, before TSS/360, TSO, or any other official time-sharing solution from IBM. This was roughly the same time that third-party time-sharing systems such as MTS became available and the under the radar development effort of CP-67 at IBM's own Cambridge Scientific Center took place. WYLBUR had the additional advantage that it could be used in conjunction with IBM's mainstream operating system, OS/360.

WYLBUR is a single-address-space system, unlike TSO. This conserved memory in the days when memory was precious. So even when TSO was available, organizations seeking to minimize memory use would often keep some or even a majority of their users on WYLBUR rather than letting them use the TSO interactive environment.

WYLBUR provided compressed Partitioned Data Sets (PDSs, aka libraries) to save disk space. In MVS source code was typically stored as a sequence of card images (80 character lines). If a line contained only one or just a few characters, too bad, 80 characters were still used to store that line. Even when data, e.g., source code, were stored as variable blocked (VB), space could be wasted on strings of embedded blanks. WYLBUR implements stream-oriented storage of text in PDSs, so that a one character line might only take 16 characters (line length, offset, chunk length, character) rather than 80 to store. An external program run via JCL was used to convert files to and from the WYLBUR compressed PDS format.

Although TSO allowed a user to do more than a locked-down WYLBUR system did, it was possible to write WYLBUR Exec scripts that executed batch jobs to perform functions that ordinarily would have required a TSO account, filling a batch job skeleton out with parameters, submitting the batch job, retrieving the output and displaying it on the screen.

WYLBUR had some security advantages over TSO, and some disadvantages. Advantages included:

Disadvantages related to security included:

References

  1. ^ a b c ORVYL/370 Timesharing System Functional Description, Stanford University, 1978
  2. ^ a b WYLBUR Reference Manual, Stanford University, 1984
  3. ^ Using its own markup language
  4. ^ "WYLBUR Will Be Retiring", Titan News, Center for Information Technology, National Institutes of Health (NIH), April 7, 2009
  5. ^ ORVYL, WYLBUR, and MILTEN source and documentation, available for free as Open Source from Stanford University under a license modeled after the "Mozilla 1.1 License" certified by the "Open Source Initiative (OSI)"
  6. ^ "Computing at CERN: the mainframe era", Chris Jones, CERN Courier, September 6, 2004

External links