16 Sep
2023
16 Sep
'23
7:13 p.m.
On 9/16/23, Paul Koning via cctalk <cctalk(a)classiccmp.org> wrote:
In this video <https://www.youtube.com/watch?v=YeEB2Lxbfa4>, they
definitely appear to be some kind of video displays, since they show
graphics before takeoff and have a very noticeable refresh. These
almost certainly were a later addition, presumably replacing the
7-segment displays that Tim mentioned (which can be seen at
<https://www.flickr.com/photos/peterdenton/2380507590>).
I want to guess it was individual digits back-projected - which was a
popular control-theater display tech at the end of the 20th century - but
I can't rule out, say, really well-done edge-lit character plates. In any
event there doesn't seem to be any visible jitter up and down between
digits that I might expect with either of those technologies.
I would make the same guess. They look a bit like the IEE "In line display"
numeric projection displays that were popular in the 1960s. I have a
couple, they are very nice high quality (very readable) numeric displays
using a set of mini-projectors each with its own incandescent lamp to
project a digit onto a frosted glass (or plastic) screen.
https://www.industrialalchemy.org/articleview.php?item=511
The Concorde displays are not those exact units but they may well use the
same technology, or perhaps even use a custom-made variant.
paul