Another Look At Those Fiber Optic Displays
Added 2023-01-26 17:36:11 +0000 UTCIt's deja vu all over again! People wanted a closer look, so here we go... Enjoy!
Comments
This reminds me of the way 5x7 dot matrix characters were printed on the top of cards punched by the IBM 029 interpreting keypunch. Just as the fiber optic strands spread out to the front face of this great display, in the keypunch, stiff spring steel wires will run through channels in a block, forming the 5x7 matrix right above where the printing ribbon barely touched the cards as they went through. There was a small, machined steel plate, maybe an inch and a half by two inches, which was machined out, leaving little points sticking up from the plate. It was impossible to make out any characters, as the way the character was selected was the plate was moved in two axes, and as the wires spread out to match the dimensions of the plate, but a bit smaller to allow the plate to move and never uncover the wire array block, and when the character was printed, the plate was slammed into the block, pushing only the wires that were above one of the unmachined bumps on the plate, as appropriate. I watched as an IBM so-called SE (Service Engineer) replaced one of these plates because it was printing some letters without some of their dots. He gave me the old one, and I wrote a little program to map out the matrix and print out all of the letters corresponding to XY coordinates chosen to move the virtual plate over the virtual wire block. I printed it on a high-end version of the IBM 1403 printer, with a train of character slugs rather than a chain, and watched the letters pop out at 1100 lines a minute, each letter taking one page as I mapped the dots with lots of asterisks. As it was printing, one of my fellow Systems Programmers walked by and said, "hey, that looks like the key punch with the bed letter K!" I think I know where the plate is, after 50 years, and if I find it I'll post the picture on this thread. Meanwhile, here's a much better description of what they referred to as punch card typography. http://ibm-1401.info/PunchedCardTypography.html
Jeffrey R. Broido
2023-01-27 23:02:46 +0000 UTCFurther to my comment on the first video, I now have a model of the front module suitable for SLA 3D printing. But I think the very small holes will get clogged with resin and I doubt it will be possible to insert the optical fibres. I'm going to give it a go though, and see what happens.
David Peaker
2023-01-26 21:39:24 +0000 UTC
