14 Jul
2003
14 Jul
'03
12:31 p.m.
Sellam wrote:
... SIZE has been written to work with a GP-7
Grafbar Sonic Digitizer, manufactured
by Science Accessories Corporation, 970 Kings Highway West, Southport ...
biochem.otago.ac.nz/resource/gsize_doc.html - 33k - Cached
<http://216.239.51.104/search?q=cache:xcKrL5E0pMAJ:biochem.otago.ac.nz/resource/gsize_doc.html+%22sonic+digitizer%22+%22science+accessories%22&hl=en&ie=UTF-8>
- Similar pages
</search?hl=en&lr=&ie=UTF-8&oe=UTF-8&q=related:biochem.otago.ac.nz/resource/gsize_doc.html>
Mike
In the late 1970s, AT&T's Bell Labs invented
the "electronic blackboard".
It was basically a digitizing tablet that allowed one to draw and transmit
images.
Might anyone know where one exists? How about similar
products prior to
December 1979? When was the first digitizing tablet invented?
This is research I'm conducting for a client, so
any useful leads will be
compensated.
Thanks!
I know we had a graphics tablet at the Bioengineering Program at the University
of Missouri in 1975. It was a GrafPen Model (SP?). It consisted of two arrays of
microphones along the x and y axis of a plexiglas tablet.
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There was a spark gap pen that generated a click and the microphones could locate the
point on the tablet. It could be flipped right or left handed because your hand/arm
could block the sound from the microphones. It had a digital readout of the x and y
coordinates.
There was also a serial interface which we connected to our PDP-11/20. We placed the
tablet over a illuminated light box with a chest radiograph on it and then we able to
outline the
margins of the human heart on the film. The data was used in a project to compute the
shape of the heart and attempt to catagorize the type of congenital heart defect.
I used it to place boxes on the film to look at pulmonary vascularity.
You could imput points in a point by point mode or constant input mode. You could then
scale the points to be displayed on a graphics display such as a RAMTEK system. We
normally
would draw and display on top of the digitized film image to make sure we were registered
correctly.
There were lots of work related and fun related stuff the Grad students used to system
for.
There was a 3-dimensional model available later.
References found online:
Grafpen GP-7 sonic digitiser, manufactured by Science Accessory Corporation.
1968 - Science Accessories Corporation (later SAC) releases sonic digitizer.
GSIZE/SIZE documentation <http://biochem.otago.ac.nz/resource/gsize_doc.html
14 Jul
14 Jul
1:58 p.m.
Sellam wrote:
>In the late 1970s, AT&T's Bell Labs invented the "electronic
blackboard".
>It was basically a digitizing tablet that allowed one to draw and transmit
>images.
>Might anyone know where one exists? How about similar products prior to
>December 1979? When was the first digitizing tablet invented?
>This is research I'm conducting for a client, so any useful leads will be
>compensated.
>Thanks!
On Mon, 14 Jul 2003, McFadden, Mike wrote:
I know we had a graphics tablet at the Bioengineering
Program at the University
of Missouri in 1975. It was a GrafPen Model (SP?). It consisted of two arrays of
LOTS of digitizers existed back then.
Anyone familiar with anything prior to the Gerber Data Digitizer in 1970?
(about a meter square, horizontal and vertical crosshairs, output directly
into a 026 punch)
Anyone HAVE one? or something earlier?
The claim to have invented "electronic blackboard" has to be narrowed
SUBSTANTIALLY, as all that they did was enlarge existing digitizers to
produce one suitable for classroom/conference room wall. It was an issue
of engineering, not invention.
What about an under $10 one for a MICROCOMPUTER/PERSONAL COMPUTER?
I will lay claim to the dubious honor of inventing that. (even though
it was so obvious that MANY people must have done so)
In 1983, I wanted a digitizer for blackboards. As a "proof of
concept", I attached a one foot long piece of clear plastic (a
ruler) to the shaft of a potentiometer. At the other end of it
I attached another potentiometer, with another foot long piece
of clear plastic attached to the shaft of that one. That made
for an upper arm hinged at the edge of the board with a
potentiometer, and a forearm hinged at the end of that with a
potentiometer at the "elbow".
I connected the potentiometers and a "fire" button to a DA15,
and plugged that into the joystick board ("Analog Input Board")
of a PC. (actually, for a while, I had a DIN connector on it
for Coco).
I could read the resistance of the two pots to know the "shoulder"
and "elbow" angles, and with some trivial trigonometry in software,
knew the location of the "hand". (You know the angle of the shoulder,
the length of the upper arm, the angle of the elbow, and the length of
the forearm) At the hand end, I had a hole, so that it could be
used for digitizing existing materials, by lining up the hole and
pressing the fire button, or with a pen through the hole and
"sampling" in a loop, it could do a horrendously bad job of
digitizing handwriting.
I intended to redo it with yardsticks for blackboards (with a
chalk sized hole in the hand), but the mechanical issues of a
yardstick flopping around on the end of another yardstick were
a bit much. And a usable one would require better resolution
of the analog to digital circuitry than I could get out of the
6 bits per pot using the IBM joystick board.
--
Grumpy Ol' Fred cisin(a)xenosoft.com
7839
days inactive
7839
days old
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