Calculator displays

From: Philip.Belben_at_powertech.co.uk <(Philip.Belben_at_powertech.co.uk)>
Date: Mon May 11 10:18:42 1998

Many thanks to all who replied about calculator displays. The general
consensus seems to be that it was probably a Sharp EL9, an early and
large hand-held calc (I'm sure it was larger than my hand, but never
mind) from the early 1970s.

To clear up a few misconceptions:

It was not a Nixie tube machine. I have a nixie tube calc and a nixie
tube voltmeter, so I know what those are. Apart from the trademark
issues, I regard Nixie tubes as being ones in which you have an
electrode for each _character_ rather than each segment. Usually
digits, but as Tim pointed out, other symbols were available.

It was not a starburst display. I have seen 14 segment and 16 segment
versions, but these are still based on straight lines, not curves, and
the numerals are still the good old 7-segment ugly ones.

It was also not the display I have in my other digital voltmeter
(Dynamco, I think) which has as digits a multilayer Perspex sandwich.
Each perspex layer has a dot pattern for a character drilled in it; you
light up a character by illuminating the edge of the appropriate perspex
wafer, and total internal reflection confines the light to that wafer,
thus lighting up the dot pattern of only the one character. Neat.

I shall have a look at the website someone mentioned - thanks.

But meanwhile, can someone who has a Sharp please e-mail me with a brief
description of the segments of this 8-or-9-segment display and which
ones light up for which digits.

Many thanks.

(A bit of background:

Talking to my mother about watches, she said she never liked digital
watches because she found 7-segment characters hard to read. I
remembered this Sharp system and decided to try and find out a bit more.

I wonder if it would be possible to revive it for LCDs and things - I
still think it is much more readable than 7 seg.)

Philip.
Received on Mon May 11 1998 - 10:18:42 BST