Neon bulb logic elements link?

[Tony Duell]

>  For logic functions, diodes in general lack the ability
> to invert. This is critical for any computing of reasonable
> complexity.

Although the HP9100 kept the number of inverters as low as possible. OK, 
it uses the Q and Q/ outputs of all the 40-odd flip-flops, and I think 
there may be the odd inverter on the sideboards, but the main gating 
board contains no transistors at all -- just 1000-ish diodes.

-tony