Vintage projection display optic cell indicator

[Mac Doktor]

I just received one of these:

https://www.ebay.com/itm/115878932855

I haven't powered it up yet.

Terry Bowman, KA4HJH
"The Mac Doctor"

https://www.astarcloseup.com

"If only you could see what I've seen with your eyes."—Roy Batty, Blade Runner

[gregebert]

Unusual gizmo. I see that it's "backwards", so you need to project onto the backside of a screen. From the video it appears to have a built-in lens because the characters were nice and crisp, not blurry. Definitely would make a neat clock if you had 4 or 6 of them.

[Mac Doktor]

On Aug 20, 2023, at 6:44 PM, gregebert <greg...@hotmail.com> wrote:

Unusual gizmo. I see that it's "backwards", so you need to project onto the backside of a screen. From the video it appears to have a built-in lens because the characters were nice and crisp, not blurry.

There's a cylindrical glass lens. With a transparent screen at the focal point all of the characters should line up. The whole thing is a very rugged assembly and weighs quite a bit.

Definitely would make a neat clock if you had 4 or 6 of them.

The price seems really low to me but I don't need a clock. They would be good for one of those Mission Control displays...

[Mac Doktor]

Those sold out quick. An even better model turned up on eBay today:

https://www.ebay.com/itm/115933144124

On Aug 19, 2023, at 9:08 PM, Mac Doktor <themac...@gmail.com> wrote:

I just received one of these:

https://www.ebay.com/itm/115878932855

Terry Bowman, KA4HJH
"The Mac Doctor"

https://www.astarcloseup.com

“...the book said something astonishing, a very big thought. The stars, it said, were suns but very far away. The Sun was a star but close up.”—Carl Sagan, "The Backbone Of Night", Cosmos, 1980

[Benoit Tourret]

I saw some of them on a Control Data CDC 160A (Desk version)

there was 8 digits like that  behind a frosted glass. the bulbs 8 and nine was unused, the computer worked in octal.

no keyboard, the input was made with 24 toggle switch and a fugitive switch for "enter"

the "tower version" was only equiped with small bulbs of 3 or 4 mm as binary display.

in the early eighties, those jurassic computer where used for training purpose at the Control Data Institute.

[petehand]

These were invented around 1958 by IEE Corporation of Palo Alto, who marketed them as "In Line Readout". The original application was for early digital instruments -  I have seen a digital voltmeter with these displays driven by stepping switches. They gained a second life when somebody realized that you could put any transparency in them, and the Keeney company of Chicago put a fruit slide in them and used them in slot machines. (There was actually a very good legal reason for this - such machines were not officially "slot machines" according to the way the law was written.) Other manufacturers did the same and they became pretty much standard for gray-area slot machine in the 1960-1970 time period.

 

When the very first poker machine was invented around 1966, microprocessors hadn't been invented so video screens were out, but in Line Readouts could show suit and value.

These machines are in my personal collection, and I have several more.

I picked up a job lot of the numeric kind a few years ago and actually made a clock with them, using uniselectors.