Homebrewing a digital computer

From: Don Maslin <donm_at_cts.com>
Date: Sun Nov 12 23:11:25 2000

On 12 Nov 2000, Frank McConnell wrote:

> "ajp166" <ajp166_at_bellatlantic.net> wrote:
> > You can but nixies are a pita to drive. Of era lamping would be
> > bulb per bit. cheaper too.
>
> Hmm. I saw an interesting display device at a friend's the other day,
> 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
> illuminates one layer of plastic at the front; these layers are
> stacked and each has a digit (or other symbol, e.g. decimal point)
> etched in it (as a bunch of etched dots). There's a diagram on the
> side of each digit-box that indicates which bulb illuminates which
> digit or symbol.
>
> Anybody got any ideas about this thing? His speculation is that
> somebody didn't want to pay for nixies (but he's amazed at what these
> things must have cost to build in comparison), mine is that they
> wanted something nicer than a column of digits 0-9 with a bulb behind
> each.

They were quite popular with the early manufacturers of Digital
Voltmeters and other such equipment. Makers such as NonLinear Systems
(think Kaypro) and Electro Instruments and others whose names do not
immediately come to mind.

They permitted display of larger characters than nixies, had no high
voltage requirement, and with a filter you could make the display any
color you wanted.
                                                 - don
 
> -Frank McConnell
>
>
Received on Sun Nov 12 2000 - 23:11:25 GMT