Archived posting to the Leica Users Group, 2015/10/21

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Subject: [Leica] Babbage Difference Engine
From: gerry.walden at icloud.com (Gerry Walden)
Date: Wed, 21 Oct 2015 08:01:08 +0100
References: <8D2D9843A07B636-2730-AD1E4@webmail-vd012.sysops.aol.com> <07D71337-F646-4248-B827-A91A81A1FA44@acm.org>

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
>> 
>> 
>> _______________________________________________
>> Leica Users Group.
>> See http://leica-users.org/mailman/listinfo/lug for more information
>> 
> 
> 
> _______________________________________________
> Leica Users Group.
> See http://leica-users.org/mailman/listinfo/lug for more information



In reply to: Message from lrzeitlin at aol.com (lrzeitlin at aol.com) ([Leica] Babbage Difference Engine)
Message from kanner at acm.org (Herbert Kanner) ([Leica] Babbage Difference Engine)