Early Touch Screen Technology 1982

[Homer J Simpson]

[Nusa]

Same technology, 10 years earlier, was on Plato IV terminals:

http://knkx.org/post/timeline-history-touch-screen-technology

[vk6zgo]

Tektronix had it on TV waveform monitors in the mid 1990s
A silly application, really, because if someone puts his finger on the quite small screen, to point out a waveform anomaly, the stupid thing changes from line rate display to frame rate, or vice versa.

[james_s]

Touchscreens were stupid then and they're stupid now. They work well on smartphones and tablets due to the constraints of requiring a complex user interface on a pocket sized device but for practically everything else I hate the things. They never seem to respond properly to my fingers, same with capacitive touch buttons. I end up mashing the thing repeatedly until it finally picks up my touch.

[helius]

Resistive touch sensors are pressure-sensitive. With the other types, mashing doesn't do anything.

[james_s]

Well it does something for me. These are capacitive touch buttons on one of the products my company made, and the capacitive touchscreens on the ATMs my bank uses. I'll touch the button/screen several times and it does nothing, then I tap harder and harder, and eventually it picks up one of my taps. Multiple devices, not just one.

[helius]

I've had the issue with bank ATMs not registering a tap. I think the issue is in the computer software dropping events, not the sensor. So it's not pressing harder that makes it work, it's conforming to the profile that it's able to "see" (contact area and time difference between on/off)

[james_s]

I don't know if it's pressing harder, or more often or over a larger area or what, but I end up tapping repeatedly and it tends to get harder just out of frustration whether the force has any impact or not. I do suspect it does increase the capacitive coupling though, skin is flexible and the harder you press, the larger the contact patch to some degree. Either way most touch interfaces strike me as unreliable and cumbersome, with no tactile feedback. Unfortunately they are trendy.

[coppice]

I used to use that very terminal. I can't remember who made them. We had three types of terminal, which all looked the same from the outside - a straightforward VT100 clone; the VT100 clone with added Tek 4010 emulating graphics; and the one in the video, which added touch sensing.

[coppice]

Resistive touch sensors are pressure-sensitive. With the other types, mashing doesn't do anything.

Some approaches to capacitive touch can sense pressure. Crudely this can be done by detecting the variation as more of the skin is squashed against the panel. However it is possible to go beyond that with the right sensing technique.

There have been several touch techniques which produce a pressure sensitive response. For example, using ultrasonic sensing - where a surface wave is pinged in the X and the Y directions, and echoes are detected - produces echoes whose strength varies with the applied pressure. I was also told that a modern derivative of the infra red beam technique shown in the video, which is used in e-paper e-book readers and other applications, is also capable to detecting pressure, but I don't know how that works. Perhaps it is used a matter of the finger spreading out and interrupting more beams.

[helius]

Any touch technology can be augmented with pressure: just mount the whole thing in an elastic bumper and measure its deflection from zero...
Not as silly as it sounds. Many music keyboards with channel (not key) pressure do it that way.

[rfeecs]

This same infra-red touch screen technology was used in the HP-150, introduced in 1983:

[johnboxall]

We had that touch-screen on the Xerox 5100. Evil bastard of a machine.

[CatalinaWOW]

We had that touch-screen on the Xerox 5100. Evil bastard of a machine.

Used to love that machine.  Did lots of engineering proposals on that thing, copying bits and pieces of various things into something that looked viable.  Didn't have access to meaningful CAD at that time and drafting was at best slow for me (either done myself or farmed out to the pros), but with the scaled copy feature, scissors and scotch tape magic could happen in just a couple of hours.

[DrGeoff]

Remember the Fairlight CMI?
It had a touch screen that you used a stylus to draw the waveform and harmonics.
Incredible stuff with the technology available prior to 1979.

[xrunner]

Touchscreens were stupid then and they're stupid now. They work well on smartphones and tablets due to the constraints of requiring a complex user interface on a pocket sized device but for practically everything else I hate the things. They never seem to respond properly to my fingers, same with capacitive touch buttons. I end up mashing the thing repeatedly until it finally picks up my touch.

Yea. A mouse is better then putting your hand in front of the screen except as you say when it's a small phone or the like.

The other thing is, I can't stand finger smudgy smears on my screen. 

[james_s]

Same here, I can't stand it when somebody walks up and points out something on my screen and leaves a finger smudge, arg! 

[android]

Same here, I can't stand it when somebody walks up and points out something on my screen and leaves a finger smudge, arg! 

+1

IMHO, if you must engage in gerfingerpoken, it is polite to rotate your digit and make contact with just your fingernail.

[james_s]

Or just point from an inch or two away, it's not often that one needs to point with single pixel precision.

[Rick Law]

Same technology, 10 years earlier, was on Plato IV terminals:

http://knkx.org/post/timeline-history-touch-screen-technology

Good old PLATO!

Not just touch-screen equipped.  That PLATO terminal pictured in the article (with extra thick top) looks like it was also equipped with slide projector capable of projecting an actual film slide image super-imposed to the computer display.  That orange plasma screen was mesmerizing to look at.  512x512 (monochrome), touch-grid resolution is only 32x32.  The PLATO terminal was tied to a Control Data Corp back-end Cyber (60 bits) mainframe.

The first "on-line" dating resulting with a marriage (that I was aware of) was in 1981+-1 on this PLATO system.  Both were students at U of Delaware, met on-line (more precisely, met on PLATO), get to know each other on PLATO, arranged dates on PLATO.  later married around 1981.  The groom was my friend whom I met a few years earlier on PLATO.  I was invited to the wedding by PLATO "p-note" (email to you folks).

The article just mentioned University of Illinois used it.  While U of Illinois was "home base" to PLATO, many other education institutions used it.  Many businesses used it too (for training/education) back then.  It was possibly the most prolific touch screen terminal back then in 1970/80's.

[noidea]

This same infra-red touch screen technology was used in the HP-150, introduced in 1983:

Aah that brings back memories, my parents had one to run the accounting software for my fathers business. I remember that they hardly ever used the thermal printer on the top, there was a separate dot matrix connected to print out the invoices

Playing games was strictly verboten...  but they did buy us a Apple IIe clone for that 

[Nusa]

Same technology, 10 years earlier, was on Plato IV terminals:

http://knkx.org/post/timeline-history-touch-screen-technology

Good old PLATO!

Not just touch-screen equipped.  That PLATO terminal pictured in the article (with extra thick top) looks like it was also equipped with slide projector capable of projecting an actual film slide image super-imposed to the computer display.  That orange plasma screen was mesmerizing to look at.  512x512 (monochrome), touch-grid resolution is only 32x32.  The PLATO terminal was tied to a Control Data Corp back-end Cyber (60 bits) mainframe.

The first "on-line" dating resulting with a marriage (that I was aware of) was in 1981+-1 on this PLATO system.  Both were students at U of Delaware, met on-line (more precisely, met on PLATO), get to know each other on PLATO, arranged dates on PLATO.  later married around 1981.  The groom was my friend whom I met a few years earlier on PLATO.  I was invited to the wedding by PLATO "p-note" (email to you folks).

The article just mentioned University of Illinois used it.  While U of Illinois was "home base" to PLATO, many other education institutions used it.  Many businesses used it too (for training/education) back then.  It was possibly the most prolific touch screen terminal back then in 1970/80's.

Correct. That sliding door in the top section was for inserting the microfiche for rear projection on the plasma screen. The mechanism was pneumatic and required an external air source to operate, which usually was only provided in classrooms that used the feature. Many people exposed to Plato never saw that feature in operation, and it wasn't kept in later terminal designs.

The plasma displays were new tech, and amazingly reliable. 512x512 was a fantastic resolution for 1972, a day when most computer terminals were text-based. Remember, this was nearly 10 years before the IBM PC launched with CGA resolution (640x200 2-color mode, 320x200 4-color mode). EGA (640x350 16-colors) didn't happen until 1984. It wasn't until VGA in 1987 that you had a PC with comparable resolution.

The infrared touch screen was actually only 16x16 then (see the grid in the picture...that's actually a prototype touch panel), but good enough to make selections on-screen. They could be tempermental because dust tended to gather on the bottom-side sensors. Blowing the dust off regularly was required. This was before computer mice were a thing, so it was a useful alternative to the keyboard input.

[Rick Law]

Same technology, 10 years earlier, was on Plato IV terminals:

http://knkx.org/post/timeline-history-touch-screen-technology

Good old PLATO!

Not just touch-screen equipped.  That PLATO terminal pictured in the article (with extra thick top) looks like it was also equipped with slide projector capable of projecting an actual film slide image super-imposed to the computer display.
...
...

Correct. That sliding door in the top section was for inserting the microfiche for rear projection on the plasma screen. The mechanism was pneumatic and required an external air source to operate, which usually was only provided in classrooms that used the feature.
...
...

Yeah, and the pneumatic mechanism shakes the whole table when moving/stopping rapidly (during slide selection).

I recalled walking into U of Illinois CERL (Computer-based Education Research Lab) PLATO room and some guys were chuckling/laughing...

A very naughty fellow wrote something very naughty, and that naughty program used the slide projector to make movements to shake the whole thing - to match the action displayed on the screen.  (One can imagine the exact naughty thing that the naughty fellow wrote.)

The later "IST" terminals made by Control Data with a CRT really doesn't have the magic of the plasma PLATO terminals.  That said, the IST's 8080 CPU was fun to play with.  For that time frame, there really was very few systems that came near in terms of capability.

Now this conversation makes me want a good game of Empire or DND ....

_{Empire : 30 players Star Trek like space war game
DND : single player Dungeons and Dragons find treasure fight monsters game}

[mmagin]

Remember the Fairlight CMI?
It had a touch screen that you used a stylus to draw the waveform and harmonics.
Incredible stuff with the technology available prior to 1979.

I've always been amused by the elegant simplicity of light pens (or similar things like the gun controllers for arcade games and the NES).  Just a reasonably fast-responding photodiode/transistor, optics if it's not used right against the screen, some combination of hardware/software to measure the time from vertical retrace to the signal on the light pen.

[james_s]

Yeah those light pens and light guns are pretty cool. Because of the way they work, they will only work on a raster scan CRT display, otherwise they have no way of identifying where they are pointed.

[helius]

I believe this was mentioned here once before: vector CRT displays are also capable, in principle, of using light pens. The Sketchpad system from 1963 used a light pen to select objects on a vector display. It is true that registering the input is somewhat more complicated; you also cannot select empty space (since there is no raster).

Edit: The SAGE situation display terminal (circa 1958) also used a vector display (with Charactron!) and had a light gun to select targets (with a pistol grip, and a rubber point to hold the optics the proper distance from the screen).

[james_s]

Well the technology could be used with a vector display, at least to some extent, but the video games and light pens out there designed for raster displays will only work with a raster display, that's what I meant. I suppose I should have just said CRT display and not mentioned the raster part.

[coppice]

I believe this was mentioned here once before: vector CRT displays are also capable, in principle, of using light pens. The Sketchpad system from 1963 used a light pen to select objects on a vector display. It is true that registering the input is somewhat more complicated; you also cannot select empty space (since there is no raster).

We used to use light pens with vector scanned displayed, but we only needed to pick out things which were being displayed, and so were lit up. I did see others using light pens to pick any spot on the display by using a quick flash of a complete raster sweep, boustrophedonic style. The resulting flash was rather annoying, though.