Schematics of Atanasoff-Berry Computer logic circuits?
hilpert at cs.ubc.ca
Fri Aug 22 03:28:43 CDT 2008
der Mouse wrote:
> > It is not simply a swap of transistors for vacuum tubes, they are
> > fundamentally different approaches to gate design, at least if we're
> > talking about the common families of RTL ICs (that I've seen internal
> > schematics for).
> Well, for one thing, isn't RTL generally bipolar junction transistors?
> Vacuum tubes are operationally more like FETs than they are like BJTs.
> (A BJT is current control, current output, whereas a FET or vacuum tube
> is voltage control, current output.)
Yes, there is that distinction, but by the time you put both into full circuits
with current limiting resistors for the bipolar trans and bias resistors for
the tubes, where there is current there is voltage drop and where there is
voltage there is current flow, so I wouldn't characterise it as the primary distinction.
The structural/configuration difference between the two is more significant, if
one looks at schematics of the two gate designs.
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