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What's your favorite calculator?
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rsjsouza:

--- Quote from: rdl on October 22, 2022, 10:21:14 pm ---I have the older version of the TI Programmer. It has the little red bubble LEDs. I bought it during my quest to find a calculator with light up digits.

--- End quote ---
I also have this calculator and love it. The red display brings me back to my childhood and my dad's TI59
rsjsouza:

--- Quote from: wn1fju on October 22, 2022, 12:27:45 pm ---AC powered, Nixie tubes, fixed-point arithmetic, memory, 52 years old and going strong.  My favorite.

--- End quote ---
Beautiful model you have there. I have a nixie calculator as well (Casio AS-A), but unfortunately it is a very early model that is quite unreliable and mine works well for a few minutes before the results start going cuckoo. I still need to work on it, but the -24V MOS logic is quite difficult to get right with these cheapie logic analyzers.

My page where I have several photos of it:
https://sites.google.com/view/vbeletronico/casio-as-a-vbe-014
David Hess:
I refurbished the battery pack for an NOS (new old stock) TI-55 a couple weeks ago and found something weird.

When I originally fixed the battery pack, I tested it with the calculator and the calculator was broken.  It had never occurred to me that an NOS TI-55 would not work.  Further testing with a power supply confirmed it.

So I found a couple of junked TI-55s on Ebay and planned on replacing the processor/display board.  When the Ebay units arrived, I tested them on my power supply and they worked fine.  Then I wondered what the current draw was so I swapped test leads and ... now neither of the two TI-55s from Ebay worked.  What the hell?  I checked the test leads and they were connected correctly, so that did not make any sense, but then I noticed that the other test leads were backwards.

So I connected power backwards to the NOS TI-55 and it worked fine.  What happened is that Texas Instruments manufactured them with the red lead as negative and the black lead as positive.
rsjsouza:
This is plain evil... I put this as evil as the negative center tip on power barrel jacks of japanese musical instruments.
eti:
The one GOD gave me, in me noggin  ;)
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