On 12 Nov 2000, Frank McConnell wrote:
> "Rick Bensene" <rickb_at_bensene.com> wrote:
> > > in some sort of Genrad whatsit that he was getting ready to scrap.
> > > (He's keeping the display digits though.) Each digit is a box with a
> > > bunch of tiny incandescent bulbs mounted in the back; each bulb
>
> > Check out the following electronic calculator in my
> > museum of old calculators:
> > http://www.geocities.com/oldcalculators/canon161.html
> >
> > It uses this exact type of display. Pretty amazing stuff.
>
> Thanks. Yes, that is the same sort of thing. One difference (perhaps
> an improvement) in the Genrad digit-display modules is that the
> grain-of-wheat bulbs are just slid into tubes in the back of the
> module -- their contacts poke out the back of the module and mate up
> with spring-loaded contacts in the display chassis. Also, the modules
> slide out from the front of the unit, so replacing the bulbs is fairly
> straightforward and can be done without soldering.
>
> -Frank McConnell
>
Your description of the bulb mounting sounds more like the projection
type display wherein each bulb projected the image of a digit or
character onto a frosted plastic screeen at the viewed end. Each bulb
had a small lens associated with it to focus the image on the screen.
IIRC, they were typically about 1.5 x 2.0 x 4.0" and were constructed
from an aluminum extruded(?) box.
- don
Received on Mon Nov 13 2000 - 13:19:27 GMT