DigiBarn Stories:
The Restoration of the LINC
Commentary and Contributions from the LINC user community

The following are comments and contriubtions received from the Web by members of the extended community of LINC users or those otherwise touched by the link and its progeny.

Contribution from Howard Lewis (Oct 29, 2007)

Click for larger image

The picture was generated from data generated by the LINC. Bob Arnzen a faculty member of the Computer Research Laboratory was interested in presenting our Chinese guests with a rememberence of their visit to Saint Louis. With this in mind he decided the Saint Louis Arch would be the best bet. Bob then took a shot of the City Hall at night with the Arch in the background reflecting the moonlight off its' steel cover. Bob took the negative of the photo and using the LINC and a density measuring device he interfaced to the LINC, obtained a 90 X 90 matrix of density samples. The samples ranged in density from black to white and 6 shades of gray. The 0's in the matrix represented black and 7's represented white with intervening numbers representing the gray scale. From the mattrix a picture was generated by the dedicated duo of Gary Parker and David Shupe who specialized in printed circuit technology. They obtained a number of 1/2 inch squares of gray scale tiles and proceeded to reconstruct the picture by pasting the appropriate shade as indicated by the LINC generated matrix. Almost everyone at the Lab at that time volunteered to help. It was as you might imagine, quite an effort to assemble 8100 samples on a very large piece of cardboard. When the assembly was completed, a photograph was taken of the work and reduced to am approximate 24 X 20 picture. The results were graciously accepted by the Chinese who were pleased with the effort as well as the result of the work done on their behalf. The work was accomplished on time supported by the National Institutes of Health as well as the Advanced Research Projects Agency (ARPA) so the result is part of the Public Domain. If you would like to include the picture on your WEB site, I know that Bob Arnzen would be honored.

If you could give credit to Dave Shupe and Gary Parker. This work was accomplished in 1973 and the Chinese Visitors were from Communist China and their visit was one of the first indications of the ending of the Cold War. The LINC played a part.

Curator: Could this be one of the first computer processed (input) photographs?

Comment from C Kronenwetter (Aug 20, 2007)

I used one of the last generation of Linc computers, the PDP-12 to do image capture and processing in a nuclear medicine lab for almost 12 years. It was amazing what one could do with 4k of memory and later with 12k. (Even though 1k of it was taken up with progofop - the bios in today's terms.) The 14" display was a vast improvement over the little 5" Tektronix on the Linc-8 (where I learned to do assembly language programming). With a little modification, it was able to display images in gray scale. The other memorable day was the first operation of our Diablo 33 disk system (two 14" 2.5 MB platters which for most things replaced the use of Linctape in our lab). It was remarkable that the folks at UW Madison were able to shoehorn the code for the Diablo disk system into the leftover space in Progofop (stood for Program OF OPeration). My hearing still suffers from sitting in front of 4 cabinets of roaring cooling fans but it was the machine that got me into the back door of image processing where I have lasted for 35 years. Those were indeed the days.

From Anthony D'Atri (Aug 20, 2007)

Thanks for providing your site. On this page: https://www.digibarn.com/stories/linc/index.html it's claimed that the PDP-12 was a LINC and a PDP-8 mounted in the same cabinet. That in fact describes the LINC-8; the PDP-12 was a single processor that could execute both instruction sets.

From Dr. Bernard Weiss, Professor Department of Environmental Medicine University of Rochester Medical Center (Aug 7, 2008)

I was one of the original participants in the Linc evaluation project in 1963. I moved, with my Linc, to Rochester in 1965. See [photo above]. It shows two of my students, a technician, and an engineer I brought from Hopkins. It was taken in 1966. The student sitting on the stool, Tom Gott, used the Linc in his doctoral dissertation. He then went on to become a neurosurgeon. Bill Simon is still here, and we use his talents for projects requiring imaginative mathematics, such as pharmacokinetic modeling. My best to Severo.

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