Overlays, GKS... (Was: Re: New to list)

From: Andreas Freiherr <Andreas.Freiherr_at_Vishay.com>
Date: Mon Jan 27 12:28:30 2003


Jerome H. Fine wrote:
>>Andreas Freiherr wrote:
>>For RT-11, I earned a reputation as an "overlay expert" when I managed
>>to run several applications based on our own GKS (Graphical Kernel
>>System) library within the address space of 64kB. The overlay tree was
>>ported from RSX, and the same library was available for TOPS-10, VMS,
>>several PC (DOS) FORTRAN compilers, and one FORTRAN implementation on
>>the Atari ST.
> NOW that would be very interesting. Is there a copy of the source
> available? Was it ever submitted to DECUS?

It wasn't a full implementation of the standard. That's why we didn't
officially call it GKS, but GUGS, a German abbreviation for
device-independant graphical system. But it was sufficient to do
assorted tasks from mechanical engineering, from basic line and point
diagrams using GPL and GPM through a 3D frame drawing of machine part
derived from a CNC program, at the university of Darmstadt. However, the
stuff was developed in a commercial project, so we probably would have
needed a hard-to-get permission to offer the code to the DECUS library.
At times, I was paid from this project.

OTOH, I am certain that there is no commercial interest in this material
any more, and I definitely plan on digging out the old save set and
continue development. The bad news is that this is another project on a
long list, so maybe I need somebody to more efficiently manage my time...

I do keep a Tektronix 411x (the one with the larger screen - long time
since...) terminal at home, together with a tablet, and hope to add some
input capabilities to the library at some later time.

Once I got the task to estimate the amount of work needed to support a
given terminal (for output only). I was supposed to spend about one hour
on looking at the manual, but I came back after about one and a half
hour with a working driver for the device.

We even had a shell around GUGS that would have a call interface similar
to an older library with Benson- and Calcomp-based routines. This way,
old plot programs could be adapted to more modern devices by interfacing
them to GUGS in the shell instead of re-inventing the application.

The basic kludge with the overlay tree, developed on RSX, was to create
a separate tree for the library: this made it easy to propose a
framework .ODL file that could be readily applied to any user program,
and then optimized for either space or speed.

>>I have been using VAX/VMS since some V4.n version, around mid-80s, and
>>OpenVMS/AXP since 1992, when I had the pleasure to run a field test site
>>for V1.5, clustered with VAX/VMS V5.5. One of my projects was writing a
>>print symbiont (using the SMB$ interface to the queue manager, not PSM$
> I used a VAX/VMS system in the early 1990s and discovered all
> of the wonderful enhancements. Ever since I have attempted to
> figure out how to port some of them back down to RT-11. One
> such as the Logical Name List capability is close to completion
> as a Path Handler in RT-11. Also similar to the PATH NAME
> is DOS.

Backporting? - Oh yes, part of my diploma work was a
reduced-functionality SMG$ (VMS' Screen ManaGement routines) library for
RSX, written in MACRO-11. I use it at home for EVA, the "Electronic
Video Archive" (my private video collection is managed on a PDP-11).

Andreas Freiherr
Vishay Semiconductor GmbH, Heilbronn, Germany
Received on Mon Jan 27 2003 - 12:28:30 GMT

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