neon tube memories

[Tony Duell]

> >Quite a hack to get a counter, latch and display driver in just 8 
> >transistors!
> 
> 
> Only takes 4bits to count to 10. Though it could be a switch tail 
> ring counter.

Yes, it's a 4 bit counter (either 1242 or 1248 BCD code), so that's 4 
flip-flops. That takes 8 transsitors.

The hack is to get the latch and the display decoder/driver without using 
any more transistors.

> 
> >> A write-only neon memory would still make a nice addressable
> >> display!
> >
> >Somewhere I have a neon display which seems to be a dot-matix unit (7 dots 
> >high by perhaps 100 long) with transfer electrodes like a Dekatron tube. 
> >You apply 7 'bits' to the right hand column, then toggle the transfer 
> >electrodes appropriately and all the dots move left one column. Repeat to 
> >built up the pattern you want in the display.
> >
> >-tony
> 
> Boroughs Panaplex, I have a 32char version that I power up and it works.

No, the Panaplex is just a conventional discharge display with no memory 
function. The ones I've see are 7 segmet + point + comma, and are used, 
for example, in the HP9815 calculator.

I believe the display with built-in shift register was a Borroughs 
product, with a name something like 'Selfscan' or 'Autoscan'.

-tony