vacuum tube circuits

From: Dave Dameron <>
Date: Wed Jul 21 21:37:31 1999

At 06:26 PM 4/8/99 -0500, Lawrence wrote:
>Well, several people have asked about this book. Its "Digital Computer
>components & circuits" by R. K. Richards, 1957, reprinted 1958. He says
>its a companion book to his "arithmetic Operations in Digital Computers",
>which the bookstore also has, but thats just a general boolean-logic type
>of book.
>Anyways, the used bookstore wants $15 for it. Perhaps I should see about
>photocopying this.
>1 History & Introduction
>2 Diode switching circuits
>3 Vacuum tube systems of circuit logic
>4 Transistor systems of circuit logic
>5 magnetic core systems of circuit logic
>6 Large capacity storage: non-magnetic devices
>7 Storage on a magnetic surface
>8 Magnetic core storage
>9 Circuits and tubes for decimal counting
>10 Miscellaneous components and circuits
>11 Analog-to-digital and digital-to-analog converters
>-Lawrence LeMay
I finally found one locally through and would recommend it.
Note there is about a 10 to 1 price range there.

Chapter 4 is split between point contact and junction transistors. There is
a large section on core storage, including some configurations to
non-destructively readout the data by applying a field 90 deg. from the
normal toroidal one and looking for any sense output. None of these
configurations were used outside of a lab.

There were many unusual bistable elements discussed. One unusual one is a
ferroresonant bistable circuit. A series LC circuit is excited by AC above
the resonant frequency and the inductor is saturable. If saturation is
started, the inductance drops, the resonant frequency is increased, the
current is increased and this continues until the circuit "flips". I don't
understand how this would work if the current drops to zero every half
cycle, but it apparently worked:
Beckman Instruments sold these under tha name "Ferristor".

I wish there were some photographs in the book, both of some of the
devices, and even the packaging of the circuits for, say, an IBM 604 computer.
Received on Wed Jul 21 1999 - 21:37:31 BST

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