Calculator Comparisons

From: Dave Dameron <ddameron_at_earthlink.net>
Date: Sat Oct 23 22:32:36 1999

At 12:40 AM 10/24/99 +0100, Tony wrote:

>And yes, VF displays are almost always multiplexed The multi-digit ones
>always are, but there were some single-digit VF display tubes. Never seen
>the latter in use, though.

I have a calculator board with 12 single digit VF 7 segment displays. By
looking at the transistor placement, they appear to be multiplexed. Have
not traced the circuit to figure out how they biased each display (all the
filaments are in series). It also has a few early NEC ic's such as uPD10,
uPD16. Anyone have any data such as supply voltages for these? The neg.
sign is a neon lamp, so there is a bit of "HV" on the board.
-Dave

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Received on Sat Oct 23 1999 - 22:32:36 BST