4 ms·

This isn't nearly as technologically radical, but a Tek scope of that era that we had in the lab then had a sequential colour display. A monochrome CRT with a

This isn't nearly as technologically radical, but a Tek scope of that era that we had in the lab then had a sequential colour display. A monochrome CRT with a fast-changing electronic colour filter in front of it. Totally sharp (for the era) colour graphics with no subpixels. Until you moved your head and you briefly saw the individual colour frames. The HP stuff was stodgy and boring and predictable by comparison. The HP logic analyzers back then had a really neat touchscreen interface based on criss-crossing infrared beams in front of the CRT face. The only thing that I've ever used that felt even better than a capacitive touchscreen, though obviously lower resolution.

tverbeure 1y ago
I'm pretty sure that this TDS 684B has the same kind of CRT. When I take a photo of the display, you can often clearly see it switching from one color field to the next in the middle of the screen. As for the HP touch screen, I tore down a bunch of HP 16500A logic analyzers and reverse engineered the touch screen PCB. It uses a pretty simply LED/photo sensor matrix. You can see the PCB in one of the pictures here: https://tomverbeure.github.io/2022/06/17/HP16500a-teardown.html#tearing-down-the-logic-analyzer https://tomverbeure.github.io/2022/06/17/HP16500a-teardown.h....
- knotimpressed 1y ago
  That looks fairly similar to what the Kobo Touch still uses today! Pretty cool.
deleted 1y ago
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grishka 1y ago
Modern video projectors also display color channels sequentially and also exhibit that effect. Also, this particular CRT technology was not only used in oscilloscopes: https://www.youtube.com/watch?v=z-q8ehzHeQQ https://www.youtube.com/watch?v=z-q8ehzHeQQ
- sgerenser 1y ago
  Not all video projectors, only color wheel DLP projectors (which were once the majority of the home projector market but not sure if that’s still the case). Always drove me nuts but apparently most people don’t notice it.
- robocat 1y ago
  Skip forward to 9 minutes and the fantastic vid talks quite a bit about how Tektronix invented the LCD colour shutter tech calling it NuColor.
- djmips 1y ago
  Somewhat related but I just remember when Numega had a color image digitizer with a black and white camera and color filters for the Amiga. I guess the idea is very old because IIRC the very first color photos were taken that way. And speaking of projectors - I think there were projectors / projection TVs that used three black and white CRTS with filters that were merged to produce the final image. Could be higher resolution that way.
kevin_thibedeau 1y ago
HPs portable benchtop LAs of the that era with the same X11R5 GUI were better than the modular touchscreen lab units because on the latter you only had a jog wheel and were forced to navigate menu hierarchy with touch for everything else. The portable models had hard buttons for every major mode you'd want to switch between, plus an alpha keypad for convenient label editing.
deleted 1y ago
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tverbeure 1y ago

I'm pretty sure that this TDS 684B has the same kind of CRT. When I take a photo of the display, you can often clearly see it switching from one color field to the next in the middle of the screen. As for the HP touch screen, I tore down a bunch of HP 16500A logic analyzers and reverse engineered the touch screen PCB. It uses a pretty simply LED/photo sensor matrix. You can see the PCB in one of the pictures here: https://tomverbeure.github.io/2022/06/17/HP16500a-teardown.html#tearing-down-the-logic-analyzer https://tomverbeure.github.io/2022/06/17/HP16500a-teardown.h....

knotimpressed 1y ago
That looks fairly similar to what the Kobo Touch still uses today! Pretty cool.

deleted 1y ago

[deleted]

grishka 1y ago

Modern video projectors also display color channels sequentially and also exhibit that effect. Also, this particular CRT technology was not only used in oscilloscopes: https://www.youtube.com/watch?v=z-q8ehzHeQQ https://www.youtube.com/watch?v=z-q8ehzHeQQ

sgerenser 1y ago
Not all video projectors, only color wheel DLP projectors (which were once the majority of the home projector market but not sure if that’s still the case). Always drove me nuts but apparently most people don’t notice it.
robocat 1y ago
Skip forward to 9 minutes and the fantastic vid talks quite a bit about how Tektronix invented the LCD colour shutter tech calling it NuColor.
djmips 1y ago
Somewhat related but I just remember when Numega had a color image digitizer with a black and white camera and color filters for the Amiga. I guess the idea is very old because IIRC the very first color photos were taken that way. And speaking of projectors - I think there were projectors / projection TVs that used three black and white CRTS with filters that were merged to produce the final image. Could be higher resolution that way.

kevin_thibedeau 1y ago

HPs portable benchtop LAs of the that era with the same X11R5 GUI were better than the modular touchscreen lab units because on the latter you only had a jog wheel and were forced to navigate menu hierarchy with touch for everything else. The portable models had hard buttons for every major mode you'd want to switch between, plus an alpha keypad for convenient label editing.

deleted 1y ago

[deleted]