Cutting the front off a Burroughs SD-11 sphericular display

[AnubisTTP]

The Burroughs SD-11 sphericular display has historically been a pretty mysterious device... it has incandescent bulbs and looks like a projection display, but produces numbers using a dramatically different system. Normally SD-11s are glued shut and can't be dissembled, but I had a damaged one so I sacrificed it to the screwdriver gods and took lots of pictures explaining how this very strange device works. Enjoy!

http://www.industrialalchemy.org/articleview.php?item=626

If someone could come up with a good way to make a replacement mask, it might even be possible to change the characters displayed on one of these. I don't think a laser printer with transparency paper will work for a sphericular display like it does for projection displays; the one I cut apart above has about 4500 tiny circles printed in a 1 inch square. One would need a very high resolution printer and good transparency film to pull that off...

[redrok]

Hi Anubis;

The operation is very related to the "Digital Sundials".
I have one of the "Digital Sundials International" dials.
It works very well. Of course it reads in local "Solar" time.

I think the SD-11 works in a similar way.The sundial has a front surface with vertical
line and a similar shadow mask with lines and missing lines that form the numbers.
The sundial is unaffected by the vertical position of the sun, only to the east/west motion.

East lamp in the SD-11 has a 2 dimension mask of primary holes. One hole for each pixel
in the screen. Then a shadow mask with a hole positioned for each lamp to form the characters.

I wrote a program. years ago, to make the sundial in large size. Something I could actually make.
I suspect making a large display similar to the SD-11 would be much easier to do.
Possibly done with a PC board lithographic camera controlled with Gerber codes.

I can even see a CNC machine drilling holes in metal sheets.

redrok

[AnubisTTP]

Wow, that digital sundial is very impressive, and does look like it works on the same principle. Building a larger digital display does seem like it could solve most of the problems of making your own symbols... get a bunch of surplus magnifiers, mount them in a frame, and drill a million holes in an opaque sheet with a CNC machine to make the pixel mask. The SD-11 has is a 30x30 matrix, which would mean finding 900 identical lenses somewhere to build something of the same resolution. Time to take up acrylic casting?