[inforoots] Laser Printers

[Bill Minnick]

    I'm Bill Minnick, BSEE Norwich University, 1962, now retired.  My 
contributions at Itek between 1965 and 1981 were focused on (1) 
Computer-aided Optical Design tools (Software development, primarily on 
Control Data Computers), (2) embedded, real-time computer applications in 
control, analysis and test systems (these at Optical Systems Division, 
Lexington, MA), and (3) computer design and test for military aircraft and 
space applications at Itek, Applied Technology Division, Palo 
Alto/Sunnyvale/San Jose (see my US Patent # 4,085,4439).
    I have many stories to tell about my computer-related achievements at 
Itek during the above period, but the one Bill Selmeier asked me to recount 
relates to what I believe to be the first-ever Laser Printer Development 
(and full color, no less), accomplished by Itek, Optical Systems Division, 
Lexington, MA, in the 1971 - 1972 time frame.  The work was done under 
contract to NASA as part of the Viking Lander Development Program
    I am fortunate to have two slim folders of original information about 
Itek's role in the Viking Program.  I'll quote relevant passages about the 
laser printer from the original press information packet:
    "The result of processing is a film negative, five inches wide by one 
foot long, with the same tonal accuracy and fidelity of image as the 
original photography.  The ground reconstruction equipment (designation for 
the laser printer) can produce three types of negatives: black and white, 
composite color and color separation.  Red, blue and green radiation from 
an argon-krypton laser supplies the primary colors to scan images onto the 
film.  Each color's intensity can be controlled independently by modulators 
and shutters. The equipment can also supply a preview of a scene prior to 
the more time-consuming process of high quality reconstruction.  (my 
recollection is that pixel diameter, high resolution mode was 0.001 inches.)

   Some years ago, I wrote a summary of my recollections, having been a 
member of the 6-man Laser Printer Development Project under the Viking 
Lander Camera Contract.  I offer it here for the record:
                 In early 1971, NASA awarded the Viking Lander Camera 
Design/Development contract to my company: Itek, Optical Systems Division, 
Lexington, MA.  The contract including production of 2 camera assemblies 
for each of two lander vehicles destined for the Martian surface, and a 
test lander unit that is now on display at the Smithsonian Air and Space 
Museum, Washington, DC.  In addition to camera development, the Viking 
Lander Camera contract required development of a full-color laser printer; 
this was to be the first laser printer made for continuous duty operation.
                             There were six engineers on the Laser Printer 
development team, as I recall.  I can recall only the Project manager's 
name, Dr. Richard (Dick) Jones.  The six engineers were chosen for their 
skills in 1) System design and project management, 2) optics, 3) lasers, 4) 
mechanical design, 5) computer hardware interfacing, and 6) computer 
requirements and program development.
                    My job on the design team was the #6 slot:  to 
determine the data flow requirements to "paint out" Martian terrain photos 
on film mounted on a spinning drum, and to choose a commercial computer 
that would do the job at acceptable printing speeds and be reliable. Dr. 
Richard (Dick) Jones, a devoted DEC computer fan, was the project lead, and 
I did battle with him on the choice of computer: He wanted to use the 
latest DEC PDP-11 and I wanted to use the then new Hewlett-Packard 2100 
computer. We needed three 1-megahertz, 10-bit DMA channels to output a 
3-color pixel stream to the lasers.  The PDP-11 only offered 1 or 2 DMA 
Channels; the HP-2100 offered the three DMA channels we needed - - and we 
(our Viking Laser Printer Project) bought and received the first HP 2100 
computer which was shipped East of the Mississippi.
                     Once I had won the battle with Dick Jones and gotten 
my choice of computers to control the laser printer, I drew a scrawling 
flow chart (which I still have in my home-history files) with boxes and 
diamonds all over the large D-size paper sheet showing what had to be done 
to synchronize reading of the 9-track magnetic tape (filled with Deep Space 
Picture data from Mars) with the painting of the three 10-bit color pixels 
to the laser that beamed light on to film mounted on the rotating drum. In 
September 1971, I was asked to go to the Itek, Applied Technology Division, 
then in Palo Alto to help solve a crisis there, so I handed the rough flow 
chart and a page of calculations on Direct Memory Access timings over to 
the most trusted programmer in my group, Richard (Dick) Collier, (he was 
not the main character from the movie, Somewhere in Time), who skillfully 
implemented the assembly language code, quickly writing the laser printer 
software and getting it running without a hitch.
                    Over the next several months in 1971 and then in 1976, 
Dick Collier sent me copies of the (1) first picture taken by the Mars 
camera while being tested here on earth, then (2) the first picture 
received from Mars, and photos of the completed Laser Printer that Itek 
delivered to JPL, our Prime Contractor. The first picture the engineers 
took to test the Mars camera #1 in Lexington was the Playboy Magazine, Miss 
December, 1972 centerfold picture. I have a copy of that first "Martian" 
photo, along with a copy of the real first photo taken and received from 
Mars on July 20 1976 - - it was a black and white photo of the Lander pad 
on the Martian gravel.
                 I will post scans of the photos (less Miss December, 1972) 
in a subsequent submission.

                    Many years after Viking's successful mission in 1976, I 
learned via the Carl Sagan Cosmos series on TV (Blues for a Red Planet, 
Episode V) that on each of the two Viking Lander Vehicles was a micro-dot 
with a list of all 10,000+ people who worked on the Viking project. So I 
tell my grandchildren that, to this day, my name along with all the other 
team members appears in two places on the Planet Mars!



    
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