From: black@breeze.rsre.mod.uk (John Black)
Newsgroups: comp.lang.idl-pvwave
Subject: Re: IDL/PVWAVE History
Date: 14 Aug 92 12:35:20 GMT
Reply-To: jvb@uk.mod.hermes
Distribution: comp.lang.idl-pvwave
Organization: Defence Research Agency


 Thanks to everyone who sent me info in IDL/PV~WAVE history. No more thanks!

 I've recieved about 10 requests for this info. So I thought I'd post what
 seems to be the best of the answers I recieved. It seems to be posted in 
 response to an earlier, similar question regarding IDL/PV~WAVE history. 

					John Black.

================================================================================

thomsen@spf.trw.com (Mark R. Thomsen) writes
>David M. Legler writes
>  I assume the heritage of these packages goes back to a common ancestor
>  somewhere. What was it and how long ago did it exist ?
>
>I was told by a guy on the NCAR Graphics team that IDL, NCAR Graphics,
>and PV Wave share the same original architect/author. He said the name
>but I forgot it. When I was getting an excellent demonstration of IDL
>I mentioned this and the demo driver said he knows the originator and
>the story is true.
>
>Who is this masked man? I think IDL was the name of the original package.
>
>Mark R. Thomsen

I think I'd better clear this up before any new urban legends
are created.

IDL:
    IDL is a product of Research Systems, Inc., founded in 1977
    by David Stern. The origins of IDL were developed at the Laboratory
    for Atmospheric and Space Physics (LASP) at the University
    of Colorado. David was one of the people involved in efforts to
    make computers easier to use for the physicists at the Lab.
    The first program in the evolutionary chain to IDL was named Rufus
    (named after Dave's dog). Rufus was a very simple vector oriented
    calculator that ran on the PDP-12. It accepted 2 letter codes that
    specified (1) An arithmetic operation (2) The input registers to
    serve as operands, and (3) the destination register. The next version
    was the Mars Mariner Spectrum Editor (MMED) which was a version
    of Rufus that ran on the PDP-8.

    The next program in this line was named SOL, and it also ran on
    the PDP-8. Unlike its predecessors, SOL was a real computer language
    with a real syntax (no more 2 letter codes). It was an APL influenced
    array oriented language with some primitive graphics capabilities.
    The resemblance to IDL was there, but very faintly.

    In 1977, Dave left LASP to start Research Systems Inc. (RSI) with the
    intention of building on the ideas contained in SOL. The initial
    result of this endeavor was PDP-11 IDL, which was much more capable than
    SOL. Graphics was usually done on Tektronix terminals and outboard
    raster graphics displays. I used this version at LASP in 1981 on a
    PDP11/34 under RSX-11M in 1981 (I worked as a student at LASP from
    1981 to 1987). I didn't use it for very long though,
    because 1981 was the year that Dave released the VAX/VMS version of
    IDL. This version, which was written in VAX-11 MACRO and FORTRAN,
    took advantage of the VAX virtual memory and 32-bit address space,
    and was a huge step beyond the PDP-11 version. It used essentially
    the same sort of graphics hardware as the PDP-11.

    In 1987, Dave decided that Unix workstations were the direction in
    which IDL should progress, but porting the current VAX IDL to Unix
    didn't make much sense because of its MACRO and FORTRAN implementation.
    I had just finished my Masters degree and was looking for work.
    Dave hired me and together we wrote the current version of IDL for
    Unix on the Sun 3 taking advantage of the re-write to extend and
    improve the language. Since then, we've ported it to many Unix
    machines as well as moving it back to VMS. We have more employees
    now, but we're still developing and extending IDL as our sole product.

NCAR Graphics:
    NCAR Graphics was and is a product of the National Center for
    Atmospheric Research (NCAR). It is an extensive library of
    callable routines for producing scientific graphics. There is
    no connection the between the origins of IDL and NCAR Graphics,
    although Boulder is a small enough place that we know some of the
    people at NCAR who have worked on it. I don't know how the rumor
    above got started, but it simply didn't happen that way. Dave
    gives great IDL demos, so he is quite likely the "excellent" demo
    giver mentioned above, but somewhere down the line facts have
    become confused.

PV~WAVE:
    Anyone who reads this newsgroup regularly should know the answer to
    this. Around the time that the Unix version of IDL first became
    available (1988), Precision Visuals Inc. (PVI) entered into an agreement
    with RSI under which they enhanced and resold IDL under the name
    PV~WAVE. In September of last year, they exercised an option
    in that agreement that resulted in the following:
	- They received a copy of the IDL source code as it existed
	  in September 1990 in return for a one time payment to RSI.
	- The connection between RSI and PVI was severed. We do not
	  give them code updates, enhancements, or bug fixes of any
	  kind, and they do their own support and development.
    IDL and PV~WAVE are now on separate development tracks.

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Newsgroups: comp.lang.idl-pvwave