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
Anyways, the used bookstore wants $15 for it. Perhaps I should see about
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
I finally found one locally through www.bookfinder.com
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.