[Leica] Babbage Difference Engine

[Herbert Kanner]

Herbert Kanner
kanner at acm.org

Question Authority and the authorities will question you.

> On Oct 20, 2015, at 12:25 PM, Larry Zeitlin via LUG <lug at leica-users.org> wrote:
> 
> Herbert,From Wikipedia’s article on magnetic core memories:
> "Two key inventions led to the development of magnetic core memory in 1951. The first, An Wang's, was the write-after-read cycle, which solved the problem of how to use a storage medium in which the act of reading erased the data read enabling the construction of a serial, one-dimensional shift register of o(50) bits, using two cores to store a bit. A Wang core shift register is in the Revolution exhibit at the Computer History Museum. The second, Jay Forrester's, was the coincident-current system, which enabled a small number of wires to control a large number of cores enabling 3D memory arrays of several million bits e.g. 8K x 8K x 64 bits.”  So I guess we are both right.
> 
> 
> Now back to the Leica S. A toy for the very rich.
> 
> 
> Larry Z
> 
> 
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