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Why didn't the Whirlwind I use a high persistence crt or something ?

On this video Whirlwind I at 1:48, you can see the text being diplayed, it is only very briefly visible, apparently they would take a film picture and some hours ( or a day ) later see the results on the crt screen by looking at the developed film photo.

  • To answer the deleted question: You may need to collect a bit more reputation before you're able to comment everywhere. – Raffzahn Jun 18 at 8:19
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Why didn't the Whirlwind I use a high persistence crt or something ?

Because then no dynamic display, like the ball shown at minute 11:0, could have be done?

On this video Whirlwind I at 1:48, you can see the text being diplayed, it is only very briefly visible, apparently they would take a film picture and some hours ( or a day ) later see the results on the crt screen by looking at the developed film photo

The oscilloscope wasn't meant as primary device to display text or textual results at all, that's what the mentioned Friden Flexowriter, shown at minute 10.36 is about. It can produce printout or store results on paper tape for later processing/printing.

Developing films wasn't a matter of days, but an hour at most - keep in mind, that was right after the war, when capacities had been build to do so in minutes.

As said, the oscilloscope was meant to show (simple) graphics. Adding a camera to one was a standard method at the time to get a 'hardcopy'. To simplify/speedup handling the Whirlwind got two, one or direct view, the other for recording a picture when needed.

It's important to keep in mind that the Whirlwind wasn't any production machine like later, but an early experimental device, created to figure out the very basics of computing. And trying to show a 'full screen' of text is one of the experiments. Simply seeing if it could be done. The full result is visible at minute 11.36. For any useful text output printing it on the Flexowiter would be way more convenient, wouldn't it? Users staring 24/7 on a screen is a way later development.

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  • An adjustable-persistence storage scope would seem like it would have been optimal for this purpose, but I don't know if they were practical at the time. – supercat Jun 19 at 17:29
  • @supercat It wouldn't had made any sense at all. As seen in the clip 'printing' on the screen was only marginally faster than printing via the Fexowriter. But its not only the fact that writing on a screen is pointless from back then mindset, to draw the memory needs to hold a driver - the machine had initially only 1 Kibit RAM, later 3. That's barely enough to hold a maximum of 194 instructions. So what we see is tech demo at the very edge of development at its time.Not a CRT in the sense of way later machines. – Raffzahn Jun 19 at 18:11
  • I wasn't thinking of an adjustable-persistence scope so much as a general-purpose display device, but rather as a means of testing plotting programs before using them with live film, which I think was the main purpose of having any kind of direct-viewable scope. If it takes ten seconds to draw a chart, and parts have faded completely long before other nearby parts are drawn, it may be difficult to visually ensure that none of the captions overlap. A storage scope set for long or infinite persistence, however, would make such overlap obvious before one wastes film on a bad plot. – supercat Jun 19 at 18:41
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    @supercat For one, storage scope can not be set that way. Perisence is defined by the phosphor used. Also why asking for a new technology to be added when standard scopes and cameras are already a thing? Exposure on film can be controlled in a wide variety and it can easy be expose over minutes and hours to collect a graph. And film isn't a waste. it's the cheap medium of the time. In fact analogue photography was near it's technological height at that time. Don't think in hindsight with todays priorities. Try to get into the time and it's abilities. – Raffzahn Jun 19 at 18:55
  • When I played with a storage oscilloscope, it had a knob which, when set perfectly, would cause a drawn trace to remain on the display almost indefinitely. Setting the knob slightly counterclockwise from that ideal would result in the drawn image slowly fading; setting it slightly clockwise from there would result in the image slowly getting brighter and blooming so that after some minutes the whole screen would be lit up. How would one describe that feature if not "adjustable persistence"? – supercat Jun 19 at 19:03

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