LED Display Pinout

[cmk8895]

Something for your electronics folks who are far more up on resources than I am....

I have come by a large quantity of new old stock calculator LED displays. These are the really old ones that have itsy bitsy little LEDs then a big bubble of plastic to enlarge it so you can actually see it.

I thought they would make cool counter displays, but I haven't been able to find any pinout info, therefore can't pick a driver chip. It's a TI part, on one side of the board it says 399C, on the other 399D. 12 digit display. 21 pin.

Any pointers to something like a datasheet or just a pinout would be super. Call me silly, but I always liked the look of those old LED displays, even though you had to be at just the right angle. I think they'd make cool counter displays.

cmk

[compirate]

You mean you don't have any of those vacum tube displays?

[cmk8895]

I would LOVE to have some of those Nixie tube displays. They were cool with each little number crafted out of wire then stacked up.

What can I say, I like old tech. Oh, and I figured out the pinout. It was very simple once I got over a fundamental misunderstanding of arrays of 7-segment LCD arrays.

cmk