Quote:
Originally Posted by TonyDuell
I seem to remember that the digit counter PCBs (the ones with the nixie tubes on the front, other than the right hand digit which is different due to the higher speed needed) are an ingenious HP design. It's a BCD counter, latch and display driver in 8 transistors (and no silicon ICs).
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Yes, it's amazing. The binary (or is it biquinary? Or something else?) encoding of the counter is decoded to decimal for the nixie tubes using an array of neon bulbs and photocells deposited on a ceramic substrate. Incredibly ingenious.
Chris