[Leica] Babbage Difference Engine

[Gerry Walden]

Having not known much (if anything) about Babbage until this series of posts, I listened to a programme on BBC Radio 4 yesterday about Ada Lovelace who was closely associated with him, although maybe not as closely as she would have liked. Strange how these things suddenly come together.

Gerry


> On 20 Oct 2015, at 23:04, Herbert Kanner <kanner at acm.org> wrote:
> 
> Hi Larry,
> 
> If you’re local to the Computer History Museum, maybe we can meet there some time. I’ve been volunteering there since about 2003 or whenever it was that they moved from Moffat Field to the ex-Silicon Graphics building. I’m a docent, and do the talking part of the Babbage Engine demo at 1 pm on almost every Saturday.
> 
> Herb
> 
> 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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>> 
> 
> 
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