Oct 9 1962 - Happy Birthday LEDs!

[Lynx_Arc]

I'm the oper-ator / with my poc-ket calu-lator..

I still have my TI-30 :thumbsup:

 

[brandini]

Now that I think about it all calculators in my lifetime were LCD.

 

[Steve K]

Seriously what were early LED's used for? ....

As indicated by the venerable TI-30 (yeah, I had one too), the 7 segment LED display was a huge(!!) improvement for display technology. LED watches became the uber-geek thing to have, despite being extremely impractical (had to hit a button to light up the display). Personally, it was a big change to switch from an analog alarm clock to a LED digital clock. With the analog clock, you had to carefully tweak the "alarm" hand into position. About the best accuracy you could hope for was 5 or 10 minutes. With a digital clock with LED display, you could quickly and easily set it to the exact minute!!

Precision and accuracy was also a virtue for electronics test equipment. It was great to get a nice digital bench multi-meter with 4 or 5 digit display (glowing red LEDs)! Before that, you were basically stuck with an analog needle like the classic Simpson 260.
http://www.stevenjohnson.com/simpson/pics/simpson260.jpg
If you could get 3 digits of accuracy out of this, it was just luck.

Before 7 segment LED displays, LEDs were also used to display computer registers in the early days of computers. You would see a string of 16 LEDs, and be expected to convert it to hex or decimal by yourself. Ah.. those were the days!

edit: I have to give credit to the earlier digital numeric display technology that is known as Nixie tubes. Those were soooo cool!

 

[Lynx_Arc]

As indicated by the venerable TI-30 (yeah, I had one too), the 7 segment LED display was a huge(!!) improvement for display technology. LED watches became the uber-geek thing to have, despite being extremely impractical (had to hit a button to light up the display).

I was given an LED watch, my dad bought one then didn't like it. It took a lot of power so much that if you used it often you had to replace the batteries every 6 months. I once calculated that an LED watch used (viewed) for 1 second took the power that would run an LCD watch for over a day. I got my first LCD watch when I was 16 and it had a single button cell battery and ran for over a year.

Personally, it was a big change to switch from an analog alarm clock to a LED digital clock. With the analog clock, you had to carefully tweak the "alarm" hand into position. About the best accuracy you could hope for was 5 or 10 minutes. With a digital clock with LED display, you could quickly and easily set it to the exact minute!!

actually most LED clocks you couldn't go backwards to set them if you went past the number you had to go all the way around 23+ hours to get back again. I got a clock finally that has a reverse direction set mode.

Precision and accuracy was also a virtue for electronics test equipment. It was great to get a nice digital bench multi-meter with 4 or 5 digit display (glowing red LEDs)! Before that, you were basically stuck with an analog needle like the classic Simpson 260.
http://www.stevenjohnson.com/simpson/pics/simpson260.jpg
If you could get 3 digits of accuracy out of this, it was just luck.

accuracy of the first digital watches and clocks were a lot better than they are now, clockmakers now use atomic clocks to set themselves due to poor calibration and lower quality crystal accuracy.

Before 7 segment LED displays, LEDs were also used to display computer registers in the early days of computers. You would see a string of 16 LEDs, and be expected to convert it to hex or decimal by yourself. Ah.. those were the days!

edit: I have to give credit to the earlier digital numeric display technology that is known as Nixie tubes. Those were soooo cool!

My first calculator had a blue nixie tube display, a lot of vcrs have nixie tube displays in them also and I think even some dvd players do. I prefer LED myself or backlit LCD as nixie tech takes more power to use my TI-30 ran a lot longer than my nixie calculator the TI-30 used a 9v battery the nixie calc used 2AAs.

 

[Steve K]

My first calculator had a blue nixie tube display, a lot of vcrs have nixie tube displays in them also and I think even some dvd players do. I prefer LED myself or backlit LCD as nixie tech takes more power to use my TI-30 ran a lot longer than my nixie calculator the TI-30 used a 9v battery the nixie calc used 2AAs.

I'd like to see a picture of a blue nixie tube. I've only seen the standard reddish-orange.
As for VCR's and such, you may be thinking of a vacuum flourescent display. VFD's are still kinda neat, but a whole separate critter from nixie tubes per se.

VFD: http://en.wikipedia.org/wiki/Vacuum_fluorescent_display

Nixie tube: http://en.wikipedia.org/wiki/Nixie_tube

and in the spirit of celebrating LEDs, you can still buy gadgets using strings of LEDs to display binary data for human interpretation (marketed to techno-geeks, of course):
http://www.thinkgeek.com/product/59e0/

 

[sidecross]

The LED was one of the many off-springs of the revolution of quantum mechanics begining with the transistor developed in 1948.

 

[Lynx_Arc]

I'd like to see a picture of a blue nixie tube. I've only seen the standard reddish-orange.
As for VCR's and such, you may be thinking of a vacuum flourescent display. VFD's are still kinda neat, but a whole separate critter from nixie tubes per se.

VFD: http://en.wikipedia.org/wiki/Vacuum_fluorescent_display

Nixie tube: http://en.wikipedia.org/wiki/Nixie_tube

and in the spirit of celebrating LEDs, you can still buy gadgets using strings of LEDs to display binary data for human interpretation (marketed to techno-geeks, of course):
http://www.thinkgeek.com/product/59e0/

I guess I learn something new every day, I wonder what type of display that calculator had it wasn't separate tubes but it was around the time of LED calculators I am not sure if it was before or after them it may not have been nixie tubes after all.

 

[PhotonWrangler]

I still have my SR-10 and it still works! It was the first handheld calculator that could do square roots, and that was a big deal in electronics class. And I love those large tactile keys. The only problem with the SR-10 is that it didn't have a (good) self-test routine, so when the batteries ran low it would give you random results! I remember working on a problem with the calculator and it kept giving me nonsense answers. Finally I tried 2+2 a few times and got a wildly different answer every time. And there was no low-battery indicator to warn you that it's math had gone off the tracks.

Fortunately they fixed that problem in subsequent models.

 

[Lynx_Arc]

I still have my SR-10 and it still works! It was the first handheld calculator that could do square roots, and that was a big deal in electronics class. And I love those large tactile keys. The only problem with the SR-10 is that it didn't have a (good) self-test routine, so when the batteries ran low it would give you random results! I remember working on a problem with the calculator and it kept giving me nonsense answers. Finally I tried 2+2 a few times and got a wildly different answer every time. And there was no low-battery indicator to warn you that it's math had gone off the tracks.

Fortunately they fixed that problem in subsequent models.

I remember using my TI-30 in class and half way through a test one time it died on me so next test I showed up with a 6v lantern battery and clip leads and people looked at me weird till I hooked it up and said to them now lets see the battery die in the middle of this test I got my first LCD calculator at college and the TI-30 was retired for good but I still have it with the case and I think even the game book and manual?

 

[PhotonWrangler]

I remember using my TI-30 in class and half way through a test one time it died on me so next test I showed up with a 6v lantern battery and clip leads and people looked at me weird till I hooked it up and said to them now lets see the battery die in the middle of this test I got my first LCD calculator at college and the TI-30 was retired for good but I still have it with the case and I think even the game book and manual?

Yeah, I think that was the "Math on Keys" book?

A friend of mine had one of the original red LED wristwatches, the kind where you had to push the button to see the time. One day we were touring an AM radio station. The engineer opened up one of the doors on the transmitter - this cabinet housed a live 50kw audio modulation transformer - and my friend put his arm inside the cabinet and the wristwatch went poof. No smoke or sparks - it just suddenly didn't work anymore.

 

[Burgess]

Great thread here !


Thank you ALL for your comments and remarks.