tag:blogger.com,1999:blog-12562033287909343122024-03-17T06:34:32.626-07:00Plan 28 BlogUnknownnoreply@blogger.comBlogger31125tag:blogger.com,1999:blog-1256203328790934312.post-45658925579981563772024-02-04T01:59:00.000-08:002024-02-04T01:59:24.812-08:00January 2024 Analytical Engine Project Report<p>Project Report to Computer Conservation Society Committee for meeting 18 January 2024</p><p>Work continues apace on defining which of Babbage’s Analytical Engine designs would be meaningful to build. Tim Robinson’s extensive description and analysis of Babbage’s range of designs provides the stimulus and knowledge-base for this process. Len Shustek and Tim have been digging deeper into the algorithms and mechanical design implementation of some of Babbage’s computational processes. Their experiences are both sobering and heartening. Heartening because these are the conversations we have been waiting to have. Sobering because of the complexity of what is involved in reverse engineering detailed intention and algorithmic principles from the mechanisms depicted in the drawings and their accompanying notations. </p><p>Specifically, Tim and Len have been examining Plan 27 and Plan 28a, two advanced Babbage designs, for their viability as a build target. One outcome has been Tim’s written analyses of the levels of completeness of each of these Plans. A collateral prize has been a piece of bibliographical reconstruction to inform understanding of Plan 27. The Buxton papers held at the History of Science Museum, Oxford, contain material Babbage wrote in Florence in 1841 while he was working on Plan 27. The Buxton manuscripts are unsympathetically bound: folios are out of order, contain revisions, and material in the gutters of the spine is difficult to read. Tim has revisited the images of these manuscripts, and our transcriptions of them, to reconstruct the likeliest linear account from the patchwork quilt of the primary sources. He writes that ‘the result turns out to be one of the most coherent pieces he [Babbage] ever wrote on the Engine.’ </p><p>Devices Len and Tim have explored include the anticipating carriage mechanism, the method of division and the operation of the barrels used for ‘microprogramming’. The anticipating carriage was an early breakthrough for Babbage who wrote that the invention ‘produced an exhilaration of the spirits which not even [his host’s] excellent champagne could rival’. Len has been experimenting with algorithmic simulations, component-level simulations, and some 3D printing. These investigations deepen and extend understanding. They also agitate and inform an ongoing debate about trade-offs between manufacturing costs, historical fidelity and what is practically realisable in a foreseeable timescale. </p><p>Reflecting on Babbage’s failure to complete any of his engines Babbage’s son wrote:</p><blockquote style="border: none; margin: 0 0 0 40px; padding: 0px;"><p style="text-align: left;"><i>The History of Babbage's Calculating Machines is sufficient to damp the ardour of a dozen enthusiasts.</i></p></blockquote><blockquote style="border: none; margin: 0 0 0 40px; padding: 0px;"><p style="text-align: left;">Major-General H. P Babbage, 12 September 1888.</p></blockquote><p>I wonder if we can prove him wrong.</p><p>Doron Swade</p>Unknownnoreply@blogger.com7tag:blogger.com,1999:blog-1256203328790934312.post-14998591197989390512023-09-29T02:15:00.002-07:002023-09-29T02:15:25.056-07:00Autumn 2023 report to the Computer Conservation Society<p>Project Report to Computer Conservation Society Committee for 21 September 2023</p><p>The omission of regular reports is not indicative of a drop in activity. Quite the opposite. My last report signalled a turning point: Tim Robinson’s panoramic and detailed technical description of Babbage’s designs for the Analytical Engine put us in a position, for the first time, to specify what would be meaningful to build.</p><p>In March last year I reported that we needed to expand the team to include expertise that we did not have – primarily solid modelling and mechanical engineering, and the report was an invitation, a call, a plea, for expressions of interest to take the project forward. We have had a promising response. Len Shustek, Chairman Emeritus of the Board of Trustees of the Computer History Museum, picked up the gauntlet and set about engaging with Tim’s technical description of the AE and assessing options for going forward. This exploratory collaboration has been a welcome relief to Tim who has been working for the last six years in near-complete isolation. Discussions are ongoing about the algorithms Babbage proposed for computational process, the prospective role of various forms of simulation, and criteria of authenticity in our design of apparatus where Babbage’s provisions are less than complete. Discussions are ongoing about how to finesse the balance between fidelity to the original designs and their practical feasibility. Moving to implementation invokes issues of funding, project management, intellectual ownership, and hosting the eventual build.</p><p>Since the last report Tim has expanded the knowledge-base with an extended account of Babbage’s Mechanical Notation – Babbage’s quasi-mathematical language of signs and symbols that he used to describe mechanisms and their operation. Tim’s description includes the historical development of the Notation and Babbage’s use of it in his engine designs, especially for the Analytical Engine about which practically nothing has been published. The account runs to 16,000 words which extends the length of the overall account to some 140,000 words, a treatise that ranks as a defining treatment to date of Babbage’s work on calculating machines.</p><p>So the knowledge base is sound and provides an unprecedentedly well-founded platform for implementation.</p><p>Just over 200 years ago Babbage wrote:</p><p><i>Whether I shall construct a larger engine of this kind, and bring to perfection the others I have described, will in great measure depend on the nature of the encouragement I may receive.</i></p><p>- (Charles Babbage to Sir Humphrey Davy, 3 July 1822).</p><p>Doron Swade</p>Unknownnoreply@blogger.com4tag:blogger.com,1999:blog-1256203328790934312.post-52784837094464880722023-03-17T06:58:00.000-07:002023-03-17T06:58:41.896-07:00Spring 2023 report to the Computer Conservation Society<p><span style="background-color: white; color: #222222; font-family: Arial, Tahoma, Helvetica, FreeSans, sans-serif; font-size: 13.2px;">Project Report to Computer Conservation Society Committee for 16 March 2023</span></p><p><span style="font-family: Helvetica; font-size: 13px;">It has been a while. So, a brief recap on where we are and what we propose to do.</span></p><p class="p2" style="font-family: Helvetica; font-size: 13px; font-stretch: normal; font-variant-east-asian: normal; font-variant-numeric: normal; line-height: normal; margin: 0px; min-height: 16px;"><b>Recap</b></p><p class="p2" style="font-family: Helvetica; font-size: 13px; font-stretch: normal; font-variant-east-asian: normal; font-variant-numeric: normal; line-height: normal; margin: 0px; min-height: 16px;"><br /></p><p class="p1" style="font-family: Helvetica; font-size: 13px; font-stretch: normal; font-variant-east-asian: normal; font-variant-numeric: normal; line-height: normal; margin: 0px;">The mission of the project is to build a Babbage Analytical Engine for historical and educational purposes. Babbage left no single definitive design for an Analytical Engine. Instead there are drawings (called Plans) Babbage drafted to record developmental staging posts as his ideas evolved over a period of some 40 years. We regard an understanding of these Plans, and the design trajectory they represent, as a prerequisite of what could meaningfully be built i.e. which signature features of which design we should combine to create a machine that would best convey Babbage’s conception of an automatic digital general purpose computing machine in the 19th century.<span class="Apple-converted-space"> </span></p><p class="p2" style="font-family: Helvetica; font-size: 13px; font-stretch: normal; font-variant-east-asian: normal; font-variant-numeric: normal; line-height: normal; margin: 0px; min-height: 16px;"><br /></p><p class="p1" style="font-family: Helvetica; font-size: 13px; font-stretch: normal; font-variant-east-asian: normal; font-variant-numeric: normal; line-height: normal; margin: 0px;">In November 2021 I reported that Tim Robinson in the US had had completed the most comprehensive description yet of the Analytical Engine. The work is a product of five years research founded on a detailed review of the entire Babbage technical archive. The work analyses the workings, design and development of the machine, with a running evaluation of levels of conception, completeness, and of mechanical detail. The account runs to some 120,000 words and describes six phases of development from 1832 till Babbage’s death in 1871.<span class="Apple-converted-space"> </span></p><p class="p2" style="font-family: Helvetica; font-size: 13px; font-stretch: normal; font-variant-east-asian: normal; font-variant-numeric: normal; line-height: normal; margin: 0px; min-height: 16px;"><br /></p><p class="p1" style="font-family: Helvetica; font-size: 13px; font-stretch: normal; font-variant-east-asian: normal; font-variant-numeric: normal; line-height: normal; margin: 0px;">Since then, Tim has extended the analysis with a description of the Selecting Apparatus, a key feature of how Babbage implemented division using the selection of multiples of the divisor to be subtracted from the dividend to determine each next digit of the quotient. The description of the designs and their development, adds some 6,300 words to the earlier account. With the addition of this description, the whole account positions us to finally advance the project to the next stage – specifying what to build.</p><p class="p2" style="font-family: Helvetica; font-size: 13px; font-stretch: normal; font-variant-east-asian: normal; font-variant-numeric: normal; line-height: normal; margin: 0px; min-height: 16px;"><br /></p><p class="p1" style="font-family: Helvetica; font-size: 13px; font-stretch: normal; font-variant-east-asian: normal; font-variant-numeric: normal; line-height: normal; margin: 0px;"><b>Way Forward</b></p><p class="p2" style="font-family: Helvetica; font-size: 13px; font-stretch: normal; font-variant-east-asian: normal; font-variant-numeric: normal; line-height: normal; margin: 0px; min-height: 16px;"><br /></p><p class="p1" style="font-family: Helvetica; font-size: 13px; font-stretch: normal; font-variant-east-asian: normal; font-variant-numeric: normal; line-height: normal; margin: 0px;">We need to expand the team to include expertise we currently do not have: animation and modelling skills for simulating mechanisms, and that of mechanical engineers. In February 2022 we sought to grow the team by inviting a promising party to engage and collaborate with Tim to develop and refine the account so that it could serve as an induction and briefing document for new team members, and as the foundational reference source for design and construction. By October 2022 it was evident that this first recruiting attempt had not ignited.<span class="Apple-converted-space"> </span></p><p class="p2" style="font-family: Helvetica; font-size: 13px; font-stretch: normal; font-variant-east-asian: normal; font-variant-numeric: normal; line-height: normal; margin: 0px; min-height: 16px;"><br /></p><p class="p1" style="font-family: Helvetica; font-size: 13px; font-stretch: normal; font-variant-east-asian: normal; font-variant-numeric: normal; line-height: normal; margin: 0px;">Putting in the time and effort into preparing Tim’s account for release into the public domain would have the significant benefit of capturing and preserving the substantial advances in understanding, allowing it to serve as a launching pad for subsequent implementation. Preparing the treatise for publication for use by others would well serve both history and Babbage studies but would delay implementation by several years. The loss of momentum this would entail is a significant concern.</p><p class="p2" style="font-family: Helvetica; font-size: 13px; font-stretch: normal; font-variant-east-asian: normal; font-variant-numeric: normal; line-height: normal; margin: 0px; min-height: 16px;"><br /></p><p class="p1" style="font-family: Helvetica; font-size: 13px; font-stretch: normal; font-variant-east-asian: normal; font-variant-numeric: normal; line-height: normal; margin: 0px;">We need to attract new people committed to the mission of building a Babbage Analytical Engine and motivated to engage in the technical design challenges. We then need to attract resources to fund the project. There is currently no organisational body or institutional structure in whose name we can do this, or that can host the project or its future team.<span class="Apple-converted-space"> </span></p><p class="p2" style="font-family: Helvetica; font-size: 13px; font-stretch: normal; font-variant-east-asian: normal; font-variant-numeric: normal; line-height: normal; margin: 0px; min-height: 16px;"><br /></p><p class="p1" style="font-family: Helvetica; font-size: 13px; font-stretch: normal; font-variant-east-asian: normal; font-variant-numeric: normal; line-height: normal; margin: 0px;">So we propose to release, in piecemeal form, summary findings of Tim’s account. We propose to do this through this Website (which has carried progress reports of the project, and is the main platform of communication with the community of people who have so far expressed interest in, and support for, the venture). Tim will post installments each month summarising his descriptions of the design, insights into Babbage’s thinking, challenges, difficulties, and analysis. We hope that by sharing exposure to Babbage’s thinking in this way, an appreciation of this remarkable unbuilt machine will spread and reach those motivated to participate in its physical realisation.</p><p class="p2" style="font-family: Helvetica; font-size: 13px; font-stretch: normal; font-variant-east-asian: normal; font-variant-numeric: normal; line-height: normal; margin: 0px; min-height: 16px;"><br /></p><p class="p1" style="font-family: Helvetica; font-size: 13px; font-stretch: normal; font-variant-east-asian: normal; font-variant-numeric: normal; line-height: normal; margin: 0px;">Doron Swade</p>Unknownnoreply@blogger.com7tag:blogger.com,1999:blog-1256203328790934312.post-71339281031718751222022-02-18T10:05:00.007-08:002022-02-18T10:06:45.615-08:00January 2022 report to the Computer Conservation Society<p>Last <a href="https://blog.plan28.org/2021/12/winter-2021-report-to-computer.html">November I reported</a> on the successful completion of the first draft technical description, by Tim Robinson, of the Analytical Engine designs. Since then we have initiatives underway to increase the size of the team to take this work further. We have a separate initiative to view working papers donated by Anne Bromley, Allan Bromley’s widow. Allan Bromley, Australian computer scientist, died in 2002. His work was the first attempt to study of the detail of the Analytical Engine designs. Our study of the new Bromley papers will enable us to assess of the scope and depth of his researches and to key Tim Robinson’s findings into what was known before.</p><p>Doron Swade</p>Unknownnoreply@blogger.com4tag:blogger.com,1999:blog-1256203328790934312.post-69871537362009374072021-12-06T06:53:00.003-08:002021-12-06T06:53:37.012-08:00Winter 2021 report to the Computer Conservation Society<p>Project Report to Computer Conservation Society Committee for Meeting Thursday 18 November 2021</p><p>The project has reached a long-awaited defining point. Tim Robinson has completed the first draft of the most comprehensive description yet of the Analytical Engine designs. We have for the first time both an aerial view that integrates partial and seemingly unrelated developments, as well as the most detailed analysis yet of the specifics of implementation.</p><p>This analysis has been a prerequisite for the build. Babbage left no design for a complete Engine and the rationale for the ad hoc improvements made over thirty-eight years has not, till now, been fully investigated nor understood. We have lacked the necessary understanding to inform a meaningful build i.e. which signature features of which design should be combined to create a single representative machine.</p><p>The treatise, which is a product of five years research founded on a comprehensive review of the entire technical archive, describes six phases of development from 1832 through till Babbage’s death in 1871. At user level, Tim describes and analyses the use of punched cards, the designs for the ‘Great Operations’ (multiplication, division, square root), and for the ‘Small Operations’ (including addition, subtraction, and stepping). The description and running analysis run to some 120,000 words and includes close studies of selected mechanisms. </p><p>Our immediate next step is to structure and edit the material into a form usable by others. This is both to ensure the preservation of the knowledge the document represents, and to provide a working datum for the next stage. We are seeking to appoint someone on a funded basis to collaborate with Tim to produce a document to publishable standards.</p><p>In parallel with this we are set to examine the working papers of the late Prof. Allan Bromley. Anne Bromley, Allan’s widow, has donated three large binders of material to the Science Museum and we have made arrangements to access this material at the Science Museum Library in the Dana Centre in South Kensington. The Science Museum has kindly permitted us to copy the material for research purposes. </p><p>Bromley’s publications on the Analytical Engine are masterful, invaluable but regrettably sparse and the extent of his very considerable understanding of the designs is certainly underrepresented in his published output. The examination of these papers will, it is hoped, corroborate our new understanding as well as reveal just how far he had succeeded in decoding Babbage’s intentions.</p><p>Doron Swade</p><p> </p><p><br /></p><p> </p><div><br /></div>Unknownnoreply@blogger.com7tag:blogger.com,1999:blog-1256203328790934312.post-54441568030426085912021-09-19T09:41:00.007-07:002021-09-19T09:41:58.306-07:00Autumn 2021 report to the Computer Conservation Society<p>Submitted by Doron Swade to the <a href="http://www.computerconservationsociety.org/">Computer Conservation Society</a>.</p><p>Winding back to last Spring, with the survey of the Babbage manuscript archive complete, we were faced with the choice of pressing on to define what might be built using our current knowledge, or stepping back to evaluate and analyse what was captured in the review of the archive. We decided to step back and Tim Robinson has made substantial progress extending and integrating our understanding of the AE design and its trajectory from 1834 till Babbage’s death in 1871. Tim has identified and describes six phases in the evolution of the AE designs.</p><p>These are framed in an overview of the developmental timeline of the whole AE enterprise. There are also focussed pieces on central topics including the use of punched cards, the user view, methods of carriage of tens, and arithmetical process. This work represents the first comparative overview of each of the major designs ('Plans') and provides a new depth of understanding of the overall AE designs and of the developmental arc. The new findings vindicate the decision to take time out to process the material from the archive survey: the work will inform what can meaningful be built given that none of Babbage’s original designs describe a complete engine; secondly, the scholarly value of capturing and documenting a major advance in understanding since Bruce Collier’s work in the 1960s and Allan Bromley’s work in the 1970s and 80s. The immediate next step is to complete this analysis. The project will then move on to defining what version of the AE should be built.</p><p>Doron Swade</p>Unknownnoreply@blogger.com10tag:blogger.com,1999:blog-1256203328790934312.post-91915259945836447882021-03-25T05:23:00.000-07:002021-03-25T05:23:17.463-07:00Spring 2021 report to the Computer Conservation Society<p><span style="font-family: inherit;"><span style="background-color: white; color: #222222;">Submitted by Doron Swade to the </span><a href="http://www.computerconservationsociety.org/" style="background-color: white; color: #cc6611; text-decoration-line: none;">Computer Conservation Society</a><span style="background-color: white; color: #222222;">.</span></span></p><p><span style="font-family: inherit;">Tim Robinson has started writing up findings following the review of the complete Babbage manuscript archive. The initial work is in the form of an overview centred on each of the ‘Plans’ i.e. the large ‘systems drawings’ that Babbage shed during the evolution of the designs. The intention was to put to one side further detailed work, for the moment at least, to take stock and to document broad-stroke findings and new insights. Excavating further the hardly-known Plan 30 (there is a Plan 28a but seemingly no Plan 29) proved irresistible both for inherent interest and for completeness. Babbage restarted work on the AE designs in June 1857 after a break of almost a decade and referred to the machine as ‘Analytical Engine 30’. Tim reports that the hardware changes introduced for Plan 30 are ‘dramatic’. One remarkable feature is the extension of the Store to 1000 registers, and most intriguingly various methods of mechanically addressing the store contents. The broad-stroke writing has been paused temporarily while this rich seam is explored. It is not expected to take long and we look forward do the resumption of the interpretative account.</span></p><p><span style="font-family: inherit;">Doron Swade </span></p>Unknownnoreply@blogger.com7tag:blogger.com,1999:blog-1256203328790934312.post-79591419033223151322021-02-02T08:41:00.000-08:002021-02-02T08:41:34.887-08:00January 2021 report to the Computer Conservation Society<p>Presented by Doron Swade on Monday 21 January 2021 to the <a href="http://www.computerconservationsociety.org/">Computer Conservation Society</a>.</p><p>With the first-pass inspection of the manuscript archive complete, attention has turned to analysis and interpretation, and organising the findings to aid navigation. Babbage shed versions of the design as it developed in the form of ‘Plans’ – large ‘systems drawings’ which serve as developmental staging posts – the main ones of which number Plan 1 through to Plan 28. The overall approach to analysing the accumulated data is that of a timeline that groups all material, from wherever in the archive (drawings, Notebooks, Notations), to each of the landmark Plans.</p><p>The significance of the design advances for each Plan is identified as each is reviewed and evaluated, whether, for example, a new Plan involves a major design reset or only incremental change. From this, the first fruits of the extensive study of the sources are now emerging and the overall developmental arc is now easier to identify. A major initial finding is that the designs are less disjointed than thought and there is more continuity in the inventive trajectory than we feared was the case, or that scholarship to date had indicated. As an example of a more specific finding: it is not until Plan 27 that there is the first evidence of user-level conditional operation. While the Analytical Engine is routinely portrayed as incorporating, from the start, defining features of a modern computer conditional operation included, this feature appears fairly late in the day and is barely mentioned again. How significant to Babbage was conditional operation as a defining feature, is now an enticing open question.</p><p>This work is being undertaken by Tim Robinson in the US. Progress was slowed in by climate crises in California not to mention political and pandemic disruption. The initial findings are a long-awaited reward after some four years examining primary sources.</p><p>Doron Swade</p>Unknownnoreply@blogger.com7tag:blogger.com,1999:blog-1256203328790934312.post-83631010833422828552020-06-01T03:03:00.001-07:002020-06-02T12:00:48.862-07:00Spring 2020 report to the Computer Conservation Society<div>Presented by Doron Swade on Thursday 14 May 2020 to the <a href="http://www.computerconservationsociety.org/">Computer Conservation Society</a></div><div><br /></div><div>The Babbage technical archive held by the Science Museum has been reviewed sheet by sheet so the reference sources of AE-related content are now known. After a short hiatus Tim Robinson is carrying out the same exercise on the Babbage material in the Buxton papers held in Oxford. This material is of particular interest not least because there are several essays Babbage wrote on the Analytical Engine while in Italy immediately after his visit to Turin in 1840 where he gave his first and only seminar-lecture on the Analytical Engine at a convention of mathematicians, surveyors and scientists. This rare engagement with others was a significant stimulus to Babbage so his writings immediately following this are of special interest. We have done two substantial photo shoots (2015, 2016 and 2018) of this manuscript material, so digitised images are to hand. Part of the difficulty with is that the manuscripts are unsympathetically bound (text lost in the binding gutters), some material is undated, and the manuscripts are not bound in chronological order. We are also currently planning on the best way to document the findings so far, for wider dissemination - this a lesson learned from the material left by the late Allan Bromley who regrettably published only a small part of his deep understanding of the AE design.</div><div><br /></div><div>Doron Swade</div>Unknownnoreply@blogger.com1tag:blogger.com,1999:blog-1256203328790934312.post-83044167695225263802019-09-20T04:28:00.001-07:002019-09-20T04:28:57.878-07:00Autumn 2019 report to the Computer Conservation Society<div dir="ltr" style="text-align: left;" trbidi="on">
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<span style="font-family: Calibri; font-size: 13pt; font-variant-east-asian: normal; font-variant-ligatures: normal; font-variant-position: normal; vertical-align: baseline; white-space: pre-wrap;">This was presented by Doron Swade on September 19, 2019 to the <a href="http://www.computerconservationsociety.org/">Computer Conservation Society</a></span></div>
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<span style="font-family: Calibri; font-size: 13pt; font-variant-east-asian: normal; font-variant-ligatures: normal; font-variant-position: normal; vertical-align: baseline; white-space: pre-wrap;">In a visit from the US in March Tim Robinson reviewed a collection of ‘mystery’ material consisting of content that had eluded listing or cataloguing in earlier programmes by the Science Museum, and by Allan Bromley who produced, in 1991, the first near-comprehensive listing of the Babbage technical archive. Logging this last cache of material is now complete and it appears that only about a third of the original material survives. This estimate is based on references in the Sketchbooks to material that should be in this cache but were not found there, or elsewhere. Findings have been shared with Science Museum archivists accompanied by suggestions of how this material might fit into the structure of the new Babbage catalogue, available now online, created by the Science Museum. There is material in the Buxton archive in Oxford that awaits attention but the primary technical archive of Babbage papers held by the Science Museum has now been viewed and relevance to the AE design logged.</span></div>
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<span style="font-family: Calibri; font-size: 13pt; font-variant-east-asian: normal; font-variant-ligatures: normal; font-variant-position: normal; vertical-align: baseline; white-space: pre-wrap;">With the archive review essentially complete, a process that took over three years, Tim has shifted attention to developing a simulation environment to describe, explore, and verify the mechanical designs. So far this involves ‘logical’ simulation which features aspects of Babbage’s Mechanical Notation, the language of signs and symbols he devised to describe the machines and as a design aid, not unlike a later Hardware Description Language (HDL). Features of the Mechanical Notation that are reflected in the simulation tools include the notion of a ‘piece’ (an aggregation of parts that acts or is acted on as an ensemble), ‘working points’ (the points of influence and action between pieces), ‘assemblies’ and ‘connections’. It is hoped that this high-level simulation will be extended in due course to solid modelling and techniques for visualisation as a design aid, a manufacturing front-end, and for education.</span></div>
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<span style="font-family: Calibri; font-size: 13pt; font-variant-east-asian: normal; font-variant-ligatures: normal; font-variant-position: normal; vertical-align: baseline; white-space: pre-wrap;">Doron Swade</span></div>
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Unknownnoreply@blogger.com5tag:blogger.com,1999:blog-1256203328790934312.post-33134206166954924052019-03-22T02:53:00.003-07:002019-03-22T02:53:55.182-07:00March 2019 report to the Computer Conservation Society<div dir="ltr" style="text-align: left;" trbidi="on">
This was presented on March 21, 2019 to the <a href="http://www.computerconservationsociety.org/">Computer Conservation Society</a> by Doron Swade.<br />
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The sheet-by sheet inspection of Babbage’s vast technical archive is now in the end game after some three years. The last progress update reported that Tim Robinson, in the US, working from the digitised images of the manuscripts, was close to completing a review of the known catalogued material in the Science Museum archive and that one of the final tasks was a scrape of a relatively small but potentially critical set of drawings that had not been catalogued or scanned the contents of which are largely unknown. Tim is currently in London spending a week going through this material. This material evaded the Science Museum’s scanning operation in 2011 largely because it was not listed in the catalogue prepared by the late Allan Bromley who compiled the first near-comprehensive record, published in 1991, of the Babbage technical archive. <br /><br />There have already been significant finds. The Notations for Difference Engine 1, dating from 1834, thought to exist, had never come to light. These have now been found and represent a crucial piece in the puzzle of the developmental trajectory of the symbolic language Babbage developed as a design aid, to describe and specify his engine, and used extensively in the development of the Analytical Engine. <br /><br />Equally significant is the discovery of what is thought to be the legendary Plan 28a, part of the most advanced design for the Analytical Engine. There have been references to Plan 28 and Plan 28a designs peppered through the late manuscripts and some design drawings, but the existence of this plan has never been confirmed. Bromley told me in the late 1990s that he questioned whether it had existed as a separate entity in the first place in which event ‘Plan 28’ may have been a federation of improvements added to previous designs. <br /><br />The survey so far has identified mis-titled drawings, single drawings that have two unrelated catalogue entries, and drawings known to exist from earlier scholarly work but not located. These findings are openly shared with the Science Museum archivists in what has become a model collaboration between content specialists and archivists. We await the completion of this week’s inspection in the hope and expectation of more surprises. <br /><br />Doron Swade<br /></div>
Unknownnoreply@blogger.com4tag:blogger.com,1999:blog-1256203328790934312.post-45425561554151211592019-01-05T09:06:00.000-08:002019-01-05T09:06:28.942-08:00Autumn 2018 report to the Computer Conservation Society<div dir="ltr" style="text-align: left;" trbidi="on">
This was presented on November 15, 2018 to the <a href="http://www.computerconservationsociety.org/">Computer Conservation Society</a> by Doron Swade.<br />
<br />The end is in sight creating the cross-referenced database for the set of some 20 Scribbling Books, the manuscript notebooks in which Babbage recorded his workings and thoughts on his engine designs. Tim Robinson, who has been compiling the database is up to the last year of Babbage’s life (1871) and is within striking distance of completion. The process has taken coming up for three years.<br /><br />The motive for this undertaking was that before we could commit to building anything we needed to be sure that we had reviewed everything Babbage had to say on a particular topic. The situation is confounded by Babbage’s practice of returning to the same design issues time and time again over periods of decades as a consequence of which related material is unsystematically scattered through the archive of some 7,000 manuscript sheets.<br /><br />While Tim Robinson’s emphasis so far has been data capture rather than interpretation there are several general preliminary findings that are already invaluable to the overall enterprise of constructing an Analytical Engine. One such is the confirmation that not only are the designs incomplete with respect to details of control and overall systems integration (this was anticipated) but that there are several critical features for which there are worked viable alternatives the final selection of which Babbage left open (method of multiplication, digit precision, method of carriage, for example). Also, that Babbage remained creatively active till the end with at least one instance of his most sophisticated design being modelled in the period immediately before his death in 1871.<br /><br />The completion of the database will be a landmark in the developmental trajectory of this project. Next steps are, firstly, a scrape of a relatively small but potentially critical set of ‘mystery’ drawings that have not been catalogued or scanned. This is a manageable clean-up job undertaken for completeness and in the hope that some final gaps might be filled and some remaining blind references traced. Secondly, to model and build a mechanism (the advanced anticipating carriage mechanism) to assess logical and physical feasibility, and to use this to develop generic modelling and evaluation techniques to be extended to each of the core functions. <br /><br />Doron Swade<br /></div>
Unknownnoreply@blogger.com10tag:blogger.com,1999:blog-1256203328790934312.post-16090117742759539602018-05-18T03:50:00.000-07:002018-05-18T03:50:05.087-07:00Spring 2018 report to the Computer Conservation Society<div dir="ltr" style="text-align: left;" trbidi="on">
<span style="background-color: white; color: #222222; font-family: Arial, Tahoma, Helvetica, FreeSans, sans-serif; font-size: 13.2px;">This was presented on May 17, 2018 to the </span><a href="http://www.computerconservationsociety.org/" style="background-color: white; color: #888888; font-family: Arial, Tahoma, Helvetica, FreeSans, sans-serif; font-size: 13.2px; text-decoration-line: none;">Computer Conservation Society</a><span style="background-color: white; color: #222222; font-family: Arial, Tahoma, Helvetica, FreeSans, sans-serif; font-size: 13.2px;"> by Doron Swade.</span><br />
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<span style="color: #222222; font-family: Arial, Tahoma, Helvetica, FreeSans, sans-serif; font-size: 13.2px;">Work continues on the cross-referenced database for Babbage’s Scribbling Books, the set of </span><span style="color: #222222; font-family: Arial, Tahoma, Helvetica, FreeSans, sans-serif; font-size: 13.2px;">manuscript notebooks Babbage used to record his daily deliberations. The database marathon </span><span style="color: #222222; font-family: Arial, Tahoma, Helvetica, FreeSans, sans-serif; font-size: 13.2px;">has been undertaken by Tim Robinson in the US and the most recent work takes us to the mid-</span><span style="color: #222222; font-family: Arial, Tahoma, Helvetica, FreeSans, sans-serif; font-size: 13.2px;">1860s (Babbage died in 1871). Tim reports that this later content is fragmented and not as </span><span style="color: #222222; font-family: Arial, Tahoma, Helvetica, FreeSans, sans-serif; font-size: 13.2px;">systematically referenced by Babbage to the mechanical drawings as is his earlier work. This </span><span style="color: #222222; font-family: Arial, Tahoma, Helvetica, FreeSans, sans-serif; font-size: 13.2px;">kicks the interpretative can down the road somewhat as once the transcriptions are complete </span><span style="color: #222222; font-family: Arial, Tahoma, Helvetica, FreeSans, sans-serif; font-size: 13.2px;">this content will need to be revisited to integrate it into the larger picture. Page-by-page </span><span style="color: #222222; font-family: Arial, Tahoma, Helvetica, FreeSans, sans-serif; font-size: 13.2px;">inspection, while exacting, has the rewards of close reading one of which is revealing new </span><span style="color: #222222; font-family: Arial, Tahoma, Helvetica, FreeSans, sans-serif; font-size: 13.2px;">content in the cracks. Here is one such: in the context of manufacturing methods Babbage </span><span style="color: #222222; font-family: Arial, Tahoma, Helvetica, FreeSans, sans-serif; font-size: 13.2px;">calculates that the total number of teeth to be formed for a store with 1,000 registers would be </span><span style="color: #222222; font-family: Arial, Tahoma, Helvetica, FreeSans, sans-serif; font-size: 13.2px;">1,800,000.</span><br />
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<span style="color: #222222; font-family: Arial, Tahoma, Helvetica, FreeSans, sans-serif;"><span style="font-size: 13.2px;">The Science Museum’s small store at Blythe House has been cleared and a missing Scribbling </span></span><span style="color: #222222; font-family: Arial, Tahoma, Helvetica, FreeSans, sans-serif; font-size: 13.2px;">Book has come to light. A microfiche from the 1970s, illegible in places, was all that was </span><span style="color: #222222; font-family: Arial, Tahoma, Helvetica, FreeSans, sans-serif; font-size: 13.2px;">thought to have survived. The Museum generously made the re-found volume available at its </span><span style="color: #222222; font-family: Arial, Tahoma, Helvetica, FreeSans, sans-serif; font-size: 13.2px;">excellent viewing facilities in the Dana Centre, South Kensington, and we have photographed </span><span style="color: #222222; font-family: Arial, Tahoma, Helvetica, FreeSans, sans-serif; font-size: 13.2px;">the volume using a copying rostrum as an interim measure to resolve by comparison unclear </span><span style="color: #222222; font-family: Arial, Tahoma, Helvetica, FreeSans, sans-serif; font-size: 13.2px;">material in the microfiche. The Museum intends to digitise the volume in due course and add it </span><span style="color: #222222; font-family: Arial, Tahoma, Helvetica, FreeSans, sans-serif; font-size: 13.2px;">to the online digital archive.</span><br />
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<span style="color: #222222; font-family: Arial, Tahoma, Helvetica, FreeSans, sans-serif;"><span style="font-size: 13.2px;">A new development comes in the form of Pip Meadway, a volunteer who has generously been </span></span><span style="color: #222222; font-family: Arial, Tahoma, Helvetica, FreeSans, sans-serif; font-size: 13.2px;">transcribing manuscripts. Using captured digital images of the sources he has transcribed </span><span style="color: #222222; font-family: Arial, Tahoma, Helvetica, FreeSans, sans-serif; font-size: 13.2px;">material from the Cambridge Scribbling Book. He is currently working on images of the essays </span><span style="color: #222222; font-family: Arial, Tahoma, Helvetica, FreeSans, sans-serif; font-size: 13.2px;">on the Analytical Engine Babbage wrote while travelling in Italy after his memorable visit to a </span><span style="color: #222222; font-family: Arial, Tahoma, Helvetica, FreeSans, sans-serif; font-size: 13.2px;">convention in Turin in 1841 where he gave his one and only lecture on the AE designs. The </span><span style="color: #222222; font-family: Arial, Tahoma, Helvetica, FreeSans, sans-serif; font-size: 13.2px;">manuscripts are in the Buxton archive in Oxford and the archivists kindly allowed image capture </span><span style="color: #222222; font-family: Arial, Tahoma, Helvetica, FreeSans, sans-serif; font-size: 13.2px;">for the transcription work.</span><br />
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<span style="color: #222222; font-family: Arial, Tahoma, Helvetica, FreeSans, sans-serif;"><span style="font-size: 13.2px;">Doron Swade</span></span></div>
Unknownnoreply@blogger.com1tag:blogger.com,1999:blog-1256203328790934312.post-57298188986736902512018-03-19T04:26:00.003-07:002018-03-19T04:26:50.684-07:00March 2018 report to the Computer Conservation Society<div dir="ltr" style="text-align: left;" trbidi="on">
This was presented on March 15, 2018 to the <a href="http://www.computerconservationsociety.org/">Computer Conservation Society</a> by Doron Swade.<br />
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Work continues on the cross-referenced database for Babbage’s Scribbling Books, the set of manuscript notebooks Babbage used to record his daily deliberations.<br />
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Our original intention in supporting the wider release by the Science Museum of the Babbage technical archive was to enlist, in due course, the support of a wider community of interested volunteers. Until recently we have not taken up generous offers of help largely because it was not evident how our limited resources could stretch to manage an extended programme of work and to give the new input appropriate attention. A new development has been to make available for transcription by an enthusiastic volunteer images taken of the Scribbling Book held in the Cambridge Library. This trial programme has prompted us to address a number of issues: access to material that is on conditional release to the project by institutional archives; usage rights and access to the database; rights to edit, amend or add material; issues of attribution and checking to maintain the integrity of the content; and the formalisation of editorial conventions for database entries. The experiment has provided a valuable opportunity to address these and related issues in preparation for enlisting wider participation when we return to the task of interpreting the new indexed material to make a final assessment of the designs and the extent to which the material supports a consistent description of a complete machine.<br />
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The Cambridge manuscript belongs to Babbage’s later period (1850s and early 1860s) when he returned to refine and develop his earlier work. The most substantial single section consists of some 65 manuscript pages the transcription of which is now complete. Tim Robinson has vetted the transcriptions and incorporated them into the database. Preliminary review of this new material suggests that while cryptic in parts it is more coherent than previously thought and contains some potentially dramatic simplifications of implementation. This material will be the focus of close study in due course.<br />
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Doron Swade<br />
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Unknownnoreply@blogger.com2tag:blogger.com,1999:blog-1256203328790934312.post-2908077489057680912018-01-22T03:54:00.002-08:002018-01-22T03:54:11.996-08:00Winter 2017 report to the Computer Conservation Society<div dir="ltr" style="text-align: left;" trbidi="on">
<span style="background-color: white; color: #222222; font-family: Arial, Tahoma, Helvetica, FreeSans, sans-serif; font-size: 13.2px;">This was presented on January 18, 2018 to the </span><a href="http://www.computerconservationsociety.org/" style="background-color: white; color: #888888; font-family: Arial, Tahoma, Helvetica, FreeSans, sans-serif; font-size: 13.2px; text-decoration-line: none;">Computer Conservation Society</a><span style="background-color: white; color: #222222; font-family: Arial, Tahoma, Helvetica, FreeSans, sans-serif; font-size: 13.2px;"> by Doron Swade.</span><br />
<span style="background-color: white; color: #222222; font-family: Arial, Tahoma, Helvetica, FreeSans, sans-serif; font-size: 13.2px;"><br /></span>
<span style="color: #222222; font-family: Arial, Tahoma, Helvetica, FreeSans, sans-serif;"><span style="font-size: 13.2px;">Work continues compiling the searchable database for Babbage's manuscript Notebooks. This work is being done by Tim Robinson in the US. It has till now been impossible for Babbage scholars to come to definitive conclusions about aspects of the Analytical Engine design because of uncertainty as to what the Notebooks contained: we could not know whether what had already been researched was all that Babbage had to say on any particular topic, nor could we assess the degree of completeness of the designs in ignorance of what else there might be in the some two dozen volumes of his manuscript Notebooks. Digging in the final cracks has been rewarding though we have resisted spending too much time interpreting the content given that the major immediate priority is data capture and cross-indexing. </span></span><br />
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<span style="color: #222222; font-family: Arial, Tahoma, Helvetica, FreeSans, sans-serif;"><span style="font-size: 13.2px;">The question of the levels of completeness of the various designs is critical to a prospective build and new clues have emerged from the recent work. A manuscript in the Cambridge University Library contains a disconcerting observation by Babbage: that '<i>when some great improvement arose I only worked out enough to satisfy myself of its truth. I reserved the enquiry into many of its consequences as a treat when I otherwise felt indisposed to work</i>' (1860). This has bleak implications for a definitive detailed design. </span></span><br />
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<span style="color: #222222; font-family: Arial, Tahoma, Helvetica, FreeSans, sans-serif;"><span style="font-size: 13.2px;">Tim Robinson’s mining of the Notebooks revealed an entry in which Babbage refers to Plan 13 as the '<i>most complete ever made</i>' (1849). So we now have a datum set by Babbage himself by which to judge the best expectation of completeness and this promises to give us a first approximation of the size and nature of design gaps we might need to fill in the specification of a meaningfully buildable machine. </span></span><br />
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<span style="color: #222222; font-family: Arial, Tahoma, Helvetica, FreeSans, sans-serif;"><span style="font-size: 13.2px;">Continuing mining the Notebooks for the searchable cross-referenced database remains the priority for the coming months.</span></span><br />
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<span style="color: #222222; font-family: Arial, Tahoma, Helvetica, FreeSans, sans-serif;"><span style="font-size: 13.2px;">Doron Swade</span></span><br />
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Unknownnoreply@blogger.com7tag:blogger.com,1999:blog-1256203328790934312.post-37317962116611976152017-11-16T02:02:00.000-08:002017-11-16T02:02:40.740-08:00Autumn 2017 report to the Computer Conservation Society<div dir="ltr" style="text-align: left;" trbidi="on">
<span style="background-color: white; color: #222222; font-family: Arial, Tahoma, Helvetica, FreeSans, sans-serif; font-size: 13.2px;">This was presented on November 16 to the </span><a href="http://www.computerconservationsociety.org/" style="background-color: white; color: #888888; font-family: Arial, Tahoma, Helvetica, FreeSans, sans-serif; font-size: 13.2px; text-decoration-line: none;">Computer Conservation Society</a><span style="background-color: white; color: #222222; font-family: Arial, Tahoma, Helvetica, FreeSans, sans-serif; font-size: 13.2px;"> by Doron Swade.</span><br />
<span style="background-color: white; color: #222222; font-family: Arial, Tahoma, Helvetica, FreeSans, sans-serif; font-size: 13.2px;"><br /></span>
<span style="color: #222222; font-family: Arial, Tahoma, Helvetica, FreeSans, sans-serif;"><span style="font-size: 13.2px;">Work has continued steadily going through Babbage’s manuscript Sketchbooks (his working notebooks) and building up the cross reference database. As reported previously the volume of material is substantial and its organisation is not conducive to systematic study: it not indexed or themed by topic, nor is it rigorously chronological. Time and time again Babbage revisits the same or related topics over a period of decades, and these entries, many of which are cryptic, are dispersed through the twenty-five volumes comprising some 7-8,000 manuscript sheets. The cross-referenced database is being developed by Tim Robinson as a key research tool to manage this distributed content. </span></span><br />
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<span style="color: #222222; font-family: Arial, Tahoma, Helvetica, FreeSans, sans-serif;"><span style="font-size: 13.2px;">The focus for the last six months has been on the volumes most relevant to the Analytical Engine design started in 1834. Happily this main sequence of books is, for the most part, in chronological order. We have just completed Volume 5 which covers 1841–1844, and includes the most intense period of work by Babbage on Plan 28, the most advanced design for the Analytical Engine.</span></span><br />
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<span style="color: #222222; font-family: Arial, Tahoma, Helvetica, FreeSans, sans-serif;"><span style="font-size: 13.2px;">There are notable gaps corresponding to periods when Babbage was travelling. There is a separate "Travelling Scribbling Book", which has not yet been studied in detail, and we know of a significant body of manuscript material in the Buxton archive at Oxford which was written while Babbage was travelling in Europe in the early 1840s. The intention is to fill these gaps in due course. </span></span><br />
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<span style="color: #222222; font-family: Arial, Tahoma, Helvetica, FreeSans, sans-serif;"><span style="font-size: 13.2px;">While focussing on building the database, we have resisted the temptation analyse the material as we go as such analysis will be substantially assisted once the full corpus is in searchable form. Having said which, there are already new findings. A landmark drawing is Plan 25, dated 5 August 1840, which depicts the "Great Engine". This Plan provides the most complete system overview of the state of play at that time and is the most well-known of Babbage’s technical drawings. The version of the machine in Plan 25 is that Babbage presented in Turin in 1840 and on which Menabrea based his published description, which in turn prompted Ada Lovelace's famous Notes. The new finding is that there is no evidence of "user level" conditional control in this defining version of the design, this despite provision for sophisticated multi-way conditional branching at the "microcode" level. Given that the 1840 version was incapable of user-programmable conditional branching, the machine described in Plan 25 should be regarded technically as a calculator rather than a computer in the modern sense.</span></span><br />
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<span style="color: #222222; font-family: Arial, Tahoma, Helvetica, FreeSans, sans-serif;"><span style="font-size: 13.2px;">The first evidence of user-programmable conditional branching appears in an entry dated 19 March 1842 in what Babbage called the "minor operations" – ascertaining if a variable is zero, and ascertaining if a variable is + or -. This was when Babbage was well into the design of the "Small Analytical Engine" – a reduced version described in Plans 26 and 27. Work on Plan 28 (yet another complete reset) started two months later, but these “minor operations”, essential to making a "universal" machine, were carried over unchanged. It is yet to be established what suddenly triggered the addition of these operations. Babbage himself gives no hint of the reason in the Sketchbooks studied so far. </span></span><br />
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<span style="color: #222222; font-family: Arial, Tahoma, Helvetica, FreeSans, sans-serif;"><span style="font-size: 13.2px;">Some 2,100 pages have so far been cross referenced, indexed, and transcribed into the database. Though this represents only about a quarter of the total manuscript material, we are much further than a quarter of the way through the process: most of the remaining volumes are more fragmentary, contain material not related to the Analytical Engine, or contain rough drafts later transferred to the drawings and/or the notations (textual content already captured). All the remaining volumes will be worked through though these are not regarded as a priority at this time.</span></span><br />
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<span style="color: #222222; font-family: Arial, Tahoma, Helvetica, FreeSans, sans-serif;"><span style="font-size: 13.2px;">Doron Swade</span></span><br />
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Unknownnoreply@blogger.com12tag:blogger.com,1999:blog-1256203328790934312.post-53050474344928447972017-05-23T01:09:00.000-07:002017-05-23T01:09:43.876-07:00Spring 2017 report to the Computer Conservation Society<div dir="ltr" style="text-align: left;" trbidi="on">
Doron Swade gave an update on Plan 28 to the <a href="http://www.computerconservationsociety.org/">Computer Conservation Society</a> on May 19 as follows:<br />
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Excellent progress to report on the database for the Babbage technical archive. Tim Robinson in the US has produced a searchable database of all catalogued material with related content fully cross-referenced. Each item links directly to the corresponding Science Museum catalogue entry and to the recently available (low resolution) online scans of the originals. This work covers all technical drawings and related Notations (there are some 2,200 Notations for the Analytical Engine). A small amount of material that is known to exist but that is not yet in the Science Museum catalogue remains yet to be done.<br />
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Back in London I have completed a review of the 26 volumes of Babbage’s Scribbling Books – Babbage’s scratchpad daybooks. The Scribbling Books comprise 8,100 folio sides each of which has been examined for relevant content. The specific purpose of this review was to identify all material specifically relating to the Mechanical Notation, Babbage’s language of signs and symbols that he used to describe and specify his engines. At the same time other content relating to known unresolved questions was logged. The logs are intended as a retrieval and navigation tool to support ongoing research into the notational language with a view to further decoding the Analytical Engine designs.<br />
It is thought to be only the third time in history that the set of Scribbling Books has been gone through in their entirety. The only known precedents for this are the work of the late Bruce Collier, and the late Allan Bromley in the late 1960s and 70s.<br />
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The next step on the main database is to systematically go through the Scribbling Books and extract all cross references, tag subject content and transcribe significant material. This process is expected to be completed by the end of the year.<br />
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Doron Swade<br />
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Unknownnoreply@blogger.com7tag:blogger.com,1999:blog-1256203328790934312.post-75333450129254021862017-01-20T02:59:00.002-08:002017-01-20T02:59:07.436-08:00Winter 2016 report to the Computer Conservation Society<div dir="ltr" style="text-align: left;" trbidi="on">
This was presented on January 19 to the <a href="http://www.computerconservationsociety.org/">Computer Conservation Society</a> by Doron Swade.<br />
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The main activities since last report focus on the original manuscript sources of the Babbage technical archive held by the Science Museum. Since the 19 th century there have been several generations of reference systems, and with the digitisation of the archive in 2011 by the Science Museum, a further layer was added. The reference system now used by the Science Museum will be the de facto standard for future scholarship.<br />
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What we are doing is reviewing image by image the entire archive holdings (some 7000 manuscript folios) which include all surviving drawings and notations for the Analytical Engine, to reconcile their filenames and titles with the three or four earlier reference systems, to identify anomalies, relate the descriptions to the physical sources for untraced or missing material, identify phantom entries and omissions, and resolve situations in which material is known to exist or have existed for which no physical source is evident. Not all of this is straight forward and in some instances unscrambling layered inconsistent reference systems dating back to Babbage’s time has proved to be nightmarishly difficult. Several visits to the physical archive at Wroughton have been made. More will be required.<br />
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The outcome of this process will be a searchable data base, annotated and cross-referenced, that identifies all known sources, and records the status of each source including issues of provenance, anomalous reference history, with a record of links and citations to other material in the archive and elsewhere.<br />
<br />
As <a href="http://blog.plan28.org/2016/10/autumn-2016-report-to-computer.html">reported in September</a>, Tim Robinson in the US is going through all known material sheet by sheet to construct the searchable data base with estimated completion by the end of 2017. In London I am going through 20 volumes of Babbage’s ‘Scribbling Books’ page by page, transcribing AE-relevant material, to produce a searchable quick index, estimated for completion by July 2017.<br />
<br />
We are in close collaboration with the Science Museum archivists, and our findings are routinely supplied to them in support of their ongoing work to open-source this material. The main outcome to the Analytical Engine project will be a survey-knowledge of all known material relevant to the AE design, consistent indexing, and a powerful software retrieval and reference tool.<br />
<br />
While this activity is ongoing we have intermitted our efforts to reverse engineer a more complete understanding of the Analytical Engine design though, it must be said, pursuing the implications of critical new discoveries has proved, on occasions, irresistible.<br />
<br />
Doron Swade</div>
Unknownnoreply@blogger.com4tag:blogger.com,1999:blog-1256203328790934312.post-60583863884371567272016-10-07T08:00:00.001-07:002016-10-07T08:00:49.334-07:00How we got to where we are<div dir="ltr" style="text-align: left;" trbidi="on">
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<span style="font-family: Calibri;"><span style="font-size: 14.6667px;">The <a href="http://blog.plan28.org/2016/10/autumn-2016-report-to-computer.html">recent update</a> on the project reported that we have taken a strategic step away from the nuts and bolts of the mechanical drawings and are concentrating on marshalling all known archival sources that bear on the design of the Analytical Engines in its various forms.</span></span></div>
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<span style="font-family: Calibri;"><span style="font-size: 14.6667px;">Why we took this step had an unforeseen prompt.</span></span></div>
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<span style="font-family: Calibri;"><span style="font-size: 14.6667px;">Last year, 2015, marked the 200th anniversary of the birth of Augusta Ada, Countess of Lovelace, who, in 1843, wrote in collaboration with Babbage a much-debated account of the Analytical Engine. The bicentennial year focused attention on Lovelace’s life and work: symposia, colloquia, conferences, exhibitions and publications invited perspectives on the significance of Lovelace’s role. This required amongst other efforts a new and detailed look at her famous article.</span></span></div>
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<span style="font-family: Calibri;"><span style="font-size: 14.6667px;">A celebrated feature of Lovelace’s article was the inclusion of a description of how an Analytical Engine would automatically calculate Bernoulli numbers. The sequence of instructions, the presentational format of the procedures, and the representation of the changing internal states of the Engine have what we now recognise as program-like features. Nowhere does Lovelace or Babbage use the word ‘program’ but for convenience the procedures she described will continue to be referred to in what follows as ‘programs’ on the understanding that to do so is anachronistic.</span></span></div>
<h2 style="line-height: 115%; text-align: left;">
<span style="font-family: Calibri;"><span style="font-size: 14.6667px;">The Crunch</span></span></h2>
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<span style="font-family: Calibri; font-size: 14.6667px;">Rainer Glaschick in Germany was invited to create a simulation of Lovelace’s Bernoulli example for public display in an exhibition at the <a href="http://www.hnf.de/en/home.html">Heinz Nixdorf MuseumsForum</a> in Paderborn, Germany, and he embarked on the most detailed analysis to date of the algorithmic and instructional content of the example.</span></div>
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<span style="font-family: Calibri;"><span style="font-size: 14.6667px;">Rainer consulted with several others, Bernard Sufrin in Oxford, Tim Robinson in the US, me in the UK and others, to explore and clarify programming structure, underlying and implicit concepts, and hardware capability.</span></span></div>
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<span style="font-family: Calibri;"><span style="font-size: 14.6667px;">In the course of this Rainer raised searching questions about the computational requirements of the Bernoulli calculation and this prompted further questions about whether the Analytical Engine as designed by the early 1840s would have been capable of calculating the Bernoulli series as Lovelace described.</span></span></div>
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<span style="font-family: Calibri;"><span style="font-size: 14.6667px;">What emerged from Rainer’s analysis was a clearer understanding of Lovelace’s program. However, the question of whether or not the Analytical Engine of the early 1840s was capable of executing the calculation, and managing the results, pushed to the limits our understanding of the internal control of the Analytical Engine, specifically the question of the basic control arrangements between the punched cards of which there are several types, the processor (‘the Mill’) and memory (the ‘Store’).</span></span></div>
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<span style="font-family: Calibri;"><span style="font-size: 14.6667px;">Our inability to definitively answer aspects of the control arrangements was partly what prompted us to change our investigative strategy.</span></span></div>
<h2 style="line-height: 115%; text-align: left;">
<span style="font-family: Calibri;"><span style="font-size: 14.6667px;">Why is Lovelace’s Bernoulli example so difficult?</span></span></h2>
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<span style="font-family: Calibri; font-size: 14.6667px;">A taster of what Rainer’s exploration raised for us was the question of memory management.</span></div>
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<span style="font-family: Calibri;"><span style="font-size: 14.6667px;">The Bernoulli numbers form a series in which each new term is generated by a repeated set of operations.</span></span></div>
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<span style="font-family: Calibri;"><span style="font-size: 14.6667px;">Instructions are coded on Operation Cards – punched cards that specify the instruction to be performed. Associated with each Operation Card are Variable Cards that indicate where the operand is to be found in the Store, and where in the Store a result is to be placed. The relationship between an Operation Card and its Variable Cards is ‘hardwired’ i.e. the association between them is fixed and unalterable.</span></span></div>
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<span style="font-family: Calibri;"><span style="font-size: 14.6667px;"><br /></span></span></div>
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<span style="font-family: Calibri;"><span style="font-size: 14.6667px;">The Analytical Engine could automatically wind back the set of Operation Cards and rerun them in a loop a prescribed number of times. Since the Variable Cards contain a form of absolute addressing, rerunning the same physical set of Operation Cards will place each new result in the same location in memory i.e. each new result overwrites each last result and, unless printed as they are generated, intermediate results are lost.</span></span></div>
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<span style="font-family: Calibri;"><span style="font-size: 14.6667px;">For the Bernoulli calculation all prior results in the series are required for the computation of each new result. So results need to be retained in separate locations in the Store for later systematic retrieval.</span></span></div>
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<span style="font-family: Calibri;"><span style="font-size: 14.6667px;">Lovelace’s Bernoulli program describes looped iteration that does not overwrite the results register i.e. each new result is placed in a separate incremented location in the Store. Without a form of indexed or relative addressing it is not evident how this could have been done by rerunning the same set of cards and we have found no evidence in the design drawings for a relative or indexed addressing capability. The late Allan Bromley, whose work on the designs is the most detailed and penetrating to date, surmised that this is something that Babbage did not resolve.</span></span></div>
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<span style="font-family: Calibri;"><span style="font-size: 14.6667px;">One way of automatically computing a recurrent series and retaining all intermediate results would be to repeat the sequence of operations by feeding in physically repeated sets of cards but associate with each set a different Variable Card to direct each new result to a new location in the Store. This would allow automatic calculation of the Bernoulli sequence. But it is clear that Lovelace wished for a general solution as a demonstration of the complete generality of the Analytical Engine’s capabilities – enter n as the number of Bernoulli numbers needed and press ‘Go’ for the automatic generation of all n Bernoulli numbers in the series using the same looped set of Operation Cards.</span></span></div>
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<span style="font-family: Calibri;"><span style="font-size: 14.6667px;">Between 1837 and 1840 Babbage wrote some two dozen programs at least two of which involve recurrence relationships of this kind i.e. the calculation of series requiring the repetition of the same sequence of operations to generate each next term. In the two main examples each new result is generated only from the immediately prior result, and each new result overwrites its immediate predecessor. So if the nth term of a series is required the instruction set would be repeated n times and prior results, other than the (n-1)th are not material. If the prior intermediate results are needed they can be printed as they are generated, but they do not need to be retained internally in the Store to continue the series. Such recurrence relations can be computed by rerunning the same physical set of Operations and Variable Cards and overwriting each last result with each new one.</span></span></div>
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<span style="font-family: Calibri;"><span style="font-size: 14.6667px;"><br /></span></span></div>
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<span style="font-family: Calibri;"><span style="font-size: 14.6667px;">So while Babbage had described how the Engine would deal with some recurrence relationships he provided no example of a recurrence relationship that required the internal retention and reuse of all prior results. Without a systematic form of incremental addressing it is unclear that Lovelace’s Bernoulli program could run on an Analytical Engine of the early 1840s. This is part of the reason why Lovelace’s Bernoulli example is a more challenging example than any of Babbage’s earlier examples of programs.</span></span></div>
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<span style="font-family: Calibri;"><span style="font-size: 14.6667px;"><br /></span></span></div>
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<span style="font-family: Calibri;"><span style="font-size: 14.6667px;">Being unable to definitively resolve the arrangements for memory management in a decisive response to Rainer’s questions prompted us to realign our immediate objectives and to redirect our attentions to systematically master what was knowable about the Analytical Engine design – this by establishing a comprehensive database for all known technical sources, ensure that the database searchable and, perhaps most importantly given Babbage’s sometimes fragmented way of working, to internally cross-reference the material. This is a substantial task given the size of the archive but the outcome will allow a systematic analysis and reveal to what extent existing sources constitute a coherent description of a buildable machine.</span></span></div>
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<span style="font-family: Calibri;"><span style="font-size: 14.6667px;"><br /></span></span></div>
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<span style="font-family: Calibri;"><span style="font-size: 14.6667px;">Rainer Glaschick has made public his analysis of Lovelace’s Bernoulli example. His full account, Ada Lovelace's Calculation of Bernoulli's Numbers, can be found <a href="http://rclab.de/analyticalengine/lovelace_noteg_paper">here</a>.</span></span></div>
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<br /></div>
<div class="MsoNormal" style="line-height: 115%; mso-margin-bottom-alt: auto; mso-margin-top-alt: auto;">
<span style="font-family: Calibri;"><span style="font-size: 14.6667px;">Doron Swade</span></span></div>
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<span style="font-family: Calibri;"><span style="font-size: 14.6667px;">October 6, 2016</span></span></div>
</div>
Unknownnoreply@blogger.com14tag:blogger.com,1999:blog-1256203328790934312.post-63277761629094709482016-10-03T06:51:00.000-07:002016-10-03T06:51:14.937-07:00Autumn 2016 report to the Computer Conservation Society<div dir="ltr" style="text-align: left;" trbidi="on">
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<span style="font-family: Calibri;"><span style="line-height: 18.4px;">This was presented on September 22 to the <a href="http://www.computerconservationsociety.org/">Computer Conservation Society</a> by Doron Swade.</span></span></div>
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<span lang="EN-GB" style="font-family: Calibri; mso-ascii-theme-font: minor-latin; mso-hansi-theme-font: minor-latin;">The last report described that reverse engineering a coherent and consistent
understanding of the Analytical Engine design by examining the main and
best-known mechanical drawings has been less than completely successful to
date. I also described that to deal with this we have taken a step back to
marshal and review all known sources to assess the descriptive completeness of
the surviving technical information i.e. whether Babbage’s archived technical
drawings and manuscripts constitute in their entirety a coherent description of
the Engine.<o:p></o:p></span></div>
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<span lang="EN-GB" style="font-family: Calibri; mso-ascii-theme-font: minor-latin; mso-hansi-theme-font: minor-latin;"><br /></span></div>
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<span lang="EN-GB" style="font-family: Calibri; mso-ascii-theme-font: minor-latin; mso-hansi-theme-font: minor-latin;">Tim Robinson in the
US has been trawling through the entire technical archive and compiling a
searchable cross-referenced data base for all surviving technical material. In
parallel with this I am conducting a fast-track survey of some twenty
manuscript volumes of Babbage’s notebooks focussing on material on his
notational language (the Mechanical Notation) that he used to describe his
machines – this with a view to reading the notational description of the AE
designs using the decoded Notation as an interpretative tool to achieve a deeper
understanding of the designs. The data-base and trawling exercise is what has
primarily occupied us over the last four months.<o:p></o:p></span></div>
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<span lang="EN-GB" style="font-family: Calibri; mso-ascii-theme-font: minor-latin; mso-hansi-theme-font: minor-latin;"><br /></span></div>
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<span lang="EN-GB" style="font-family: Calibri; mso-ascii-theme-font: minor-latin; mso-hansi-theme-font: minor-latin;">A major step forward
in the overall project has been the online public release by the Science Museum
of the major part of the digitised archive. This has been widely anticipated
and widely welcomed. The Museum’s intention is that the images are for the time
being illustrative only in that the image resolution is sufficient to identify
the drawing and its major features, and higher resolution versions are
available on request. The current lower resolution images are sometimes
adequate for smaller manuscripts but for the larger sheets the detail of the
smaller annotations is insufficiently clear. The work of our small team is not
hampered by this as we have access to higher resolution off-line images under
licence. The relevance of the public release and the usability of the images
affect the volunteer effort of folk wishing to help the project, for which they
need access to detailed images. The good news is that the Science Museum
intends a higher resolution release of the whole archive for early in 2017, and
this will include material already digitised but not yet released online.
Feedback in response to the first release has confirmed the wider interest in
the project and the presence of fair number volunteers eager to help. We expect
to benefit from this effort more fully in the new year when the images will
support close reading.<o:p></o:p></span></div>
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<span lang="EN-GB" style="font-family: Calibri; mso-ascii-theme-font: minor-latin; mso-hansi-theme-font: minor-latin;"><br /></span></div>
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<span lang="EN-GB" style="font-family: Calibri; mso-ascii-theme-font: minor-latin; mso-hansi-theme-font: minor-latin;">In short, we are
retrenching by focussing on identifying, reviewing and indexing all known the
technical sources to serve both as a datum and as a research tool in the
pursuit of a deeper understanding of the designs.<o:p></o:p></span></div>
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<w:LsdException Locked="false" SemiHidden="true" UnhideWhenUsed="true"
Name="index heading"/>
<w:LsdException Locked="false" Priority="35" SemiHidden="true"
UnhideWhenUsed="true" QFormat="true" Name="caption"/>
<w:LsdException Locked="false" SemiHidden="true" UnhideWhenUsed="true"
Name="table of figures"/>
<w:LsdException Locked="false" SemiHidden="true" UnhideWhenUsed="true"
Name="envelope address"/>
<w:LsdException Locked="false" SemiHidden="true" UnhideWhenUsed="true"
Name="envelope return"/>
<w:LsdException Locked="false" SemiHidden="true" UnhideWhenUsed="true"
Name="footnote reference"/>
<w:LsdException Locked="false" SemiHidden="true" UnhideWhenUsed="true"
Name="annotation reference"/>
<w:LsdException Locked="false" SemiHidden="true" UnhideWhenUsed="true"
Name="line number"/>
<w:LsdException Locked="false" SemiHidden="true" UnhideWhenUsed="true"
Name="page number"/>
<w:LsdException Locked="false" SemiHidden="true" UnhideWhenUsed="true"
Name="endnote reference"/>
<w:LsdException Locked="false" SemiHidden="true" UnhideWhenUsed="true"
Name="endnote text"/>
<w:LsdException Locked="false" SemiHidden="true" UnhideWhenUsed="true"
Name="table of authorities"/>
<w:LsdException Locked="false" SemiHidden="true" UnhideWhenUsed="true"
Name="macro"/>
<w:LsdException Locked="false" SemiHidden="true" UnhideWhenUsed="true"
Name="toa heading"/>
<w:LsdException Locked="false" SemiHidden="true" UnhideWhenUsed="true"
Name="List"/>
<w:LsdException Locked="false" SemiHidden="true" UnhideWhenUsed="true"
Name="List Bullet"/>
<w:LsdException Locked="false" SemiHidden="true" UnhideWhenUsed="true"
Name="List Number"/>
<w:LsdException Locked="false" SemiHidden="true" UnhideWhenUsed="true"
Name="List 2"/>
<w:LsdException Locked="false" SemiHidden="true" UnhideWhenUsed="true"
Name="List 3"/>
<w:LsdException Locked="false" SemiHidden="true" UnhideWhenUsed="true"
Name="List 4"/>
<w:LsdException Locked="false" SemiHidden="true" UnhideWhenUsed="true"
Name="List 5"/>
<w:LsdException Locked="false" SemiHidden="true" UnhideWhenUsed="true"
Name="List Bullet 2"/>
<w:LsdException Locked="false" SemiHidden="true" UnhideWhenUsed="true"
Name="List Bullet 3"/>
<w:LsdException Locked="false" SemiHidden="true" UnhideWhenUsed="true"
Name="List Bullet 4"/>
<w:LsdException Locked="false" SemiHidden="true" UnhideWhenUsed="true"
Name="List Bullet 5"/>
<w:LsdException Locked="false" SemiHidden="true" UnhideWhenUsed="true"
Name="List Number 2"/>
<w:LsdException Locked="false" SemiHidden="true" UnhideWhenUsed="true"
Name="List Number 3"/>
<w:LsdException Locked="false" SemiHidden="true" UnhideWhenUsed="true"
Name="List Number 4"/>
<w:LsdException Locked="false" SemiHidden="true" UnhideWhenUsed="true"
Name="List Number 5"/>
<w:LsdException Locked="false" Priority="10" QFormat="true" Name="Title"/>
<w:LsdException Locked="false" SemiHidden="true" UnhideWhenUsed="true"
Name="Closing"/>
<w:LsdException Locked="false" SemiHidden="true" UnhideWhenUsed="true"
Name="Signature"/>
<w:LsdException Locked="false" Priority="1" SemiHidden="true"
UnhideWhenUsed="true" Name="Default Paragraph Font"/>
<w:LsdException Locked="false" SemiHidden="true" UnhideWhenUsed="true"
Name="Body Text"/>
<w:LsdException Locked="false" SemiHidden="true" UnhideWhenUsed="true"
Name="Body Text Indent"/>
<w:LsdException Locked="false" SemiHidden="true" UnhideWhenUsed="true"
Name="List Continue"/>
<w:LsdException Locked="false" SemiHidden="true" UnhideWhenUsed="true"
Name="List Continue 2"/>
<w:LsdException Locked="false" SemiHidden="true" UnhideWhenUsed="true"
Name="List Continue 3"/>
<w:LsdException Locked="false" SemiHidden="true" UnhideWhenUsed="true"
Name="List Continue 4"/>
<w:LsdException Locked="false" SemiHidden="true" UnhideWhenUsed="true"
Name="List Continue 5"/>
<w:LsdException Locked="false" SemiHidden="true" UnhideWhenUsed="true"
Name="Message Header"/>
<w:LsdException Locked="false" Priority="11" QFormat="true" Name="Subtitle"/>
<w:LsdException Locked="false" SemiHidden="true" UnhideWhenUsed="true"
Name="Salutation"/>
<w:LsdException Locked="false" SemiHidden="true" UnhideWhenUsed="true"
Name="Date"/>
<w:LsdException Locked="false" SemiHidden="true" UnhideWhenUsed="true"
Name="Body Text First Indent"/>
<w:LsdException Locked="false" SemiHidden="true" UnhideWhenUsed="true"
Name="Body Text First Indent 2"/>
<w:LsdException Locked="false" SemiHidden="true" UnhideWhenUsed="true"
Name="Note Heading"/>
<w:LsdException Locked="false" SemiHidden="true" UnhideWhenUsed="true"
Name="Body Text 2"/>
<w:LsdException Locked="false" SemiHidden="true" UnhideWhenUsed="true"
Name="Body Text 3"/>
<w:LsdException Locked="false" SemiHidden="true" UnhideWhenUsed="true"
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<w:LsdException Locked="false" SemiHidden="true" UnhideWhenUsed="true"
Name="Body Text Indent 3"/>
<w:LsdException Locked="false" SemiHidden="true" UnhideWhenUsed="true"
Name="Block Text"/>
<w:LsdException Locked="false" SemiHidden="true" UnhideWhenUsed="true"
Name="Hyperlink"/>
<w:LsdException Locked="false" SemiHidden="true" UnhideWhenUsed="true"
Name="FollowedHyperlink"/>
<w:LsdException Locked="false" Priority="22" QFormat="true" Name="Strong"/>
<w:LsdException Locked="false" Priority="20" QFormat="true" Name="Emphasis"/>
<w:LsdException Locked="false" SemiHidden="true" UnhideWhenUsed="true"
Name="Document Map"/>
<w:LsdException Locked="false" SemiHidden="true" UnhideWhenUsed="true"
Name="Plain Text"/>
<w:LsdException Locked="false" SemiHidden="true" UnhideWhenUsed="true"
Name="E-mail Signature"/>
<w:LsdException Locked="false" SemiHidden="true" UnhideWhenUsed="true"
Name="HTML Top of Form"/>
<w:LsdException Locked="false" SemiHidden="true" UnhideWhenUsed="true"
Name="HTML Bottom of Form"/>
<w:LsdException Locked="false" SemiHidden="true" UnhideWhenUsed="true"
Name="Normal (Web)"/>
<w:LsdException Locked="false" SemiHidden="true" UnhideWhenUsed="true"
Name="HTML Acronym"/>
<w:LsdException Locked="false" SemiHidden="true" UnhideWhenUsed="true"
Name="HTML Address"/>
<w:LsdException Locked="false" SemiHidden="true" UnhideWhenUsed="true"
Name="HTML Cite"/>
<w:LsdException Locked="false" SemiHidden="true" UnhideWhenUsed="true"
Name="HTML Code"/>
<w:LsdException Locked="false" SemiHidden="true" UnhideWhenUsed="true"
Name="HTML Definition"/>
<w:LsdException Locked="false" SemiHidden="true" UnhideWhenUsed="true"
Name="HTML Keyboard"/>
<w:LsdException Locked="false" SemiHidden="true" UnhideWhenUsed="true"
Name="HTML Preformatted"/>
<w:LsdException Locked="false" SemiHidden="true" UnhideWhenUsed="true"
Name="HTML Sample"/>
<w:LsdException Locked="false" SemiHidden="true" UnhideWhenUsed="true"
Name="HTML Typewriter"/>
<w:LsdException Locked="false" SemiHidden="true" UnhideWhenUsed="true"
Name="HTML Variable"/>
<w:LsdException Locked="false" SemiHidden="true" UnhideWhenUsed="true"
Name="Normal Table"/>
<w:LsdException Locked="false" SemiHidden="true" UnhideWhenUsed="true"
Name="annotation subject"/>
<w:LsdException Locked="false" SemiHidden="true" UnhideWhenUsed="true"
Name="No List"/>
<w:LsdException Locked="false" SemiHidden="true" UnhideWhenUsed="true"
Name="Outline List 1"/>
<w:LsdException Locked="false" SemiHidden="true" UnhideWhenUsed="true"
Name="Outline List 2"/>
<w:LsdException Locked="false" SemiHidden="true" UnhideWhenUsed="true"
Name="Outline List 3"/>
<w:LsdException Locked="false" SemiHidden="true" UnhideWhenUsed="true"
Name="Table Simple 1"/>
<w:LsdException Locked="false" SemiHidden="true" UnhideWhenUsed="true"
Name="Table Simple 2"/>
<w:LsdException Locked="false" SemiHidden="true" UnhideWhenUsed="true"
Name="Table Simple 3"/>
<w:LsdException Locked="false" SemiHidden="true" UnhideWhenUsed="true"
Name="Table Classic 1"/>
<w:LsdException Locked="false" SemiHidden="true" UnhideWhenUsed="true"
Name="Table Classic 2"/>
<w:LsdException Locked="false" SemiHidden="true" UnhideWhenUsed="true"
Name="Table Classic 3"/>
<w:LsdException Locked="false" SemiHidden="true" UnhideWhenUsed="true"
Name="Table Classic 4"/>
<w:LsdException Locked="false" SemiHidden="true" UnhideWhenUsed="true"
Name="Table Colorful 1"/>
<w:LsdException Locked="false" SemiHidden="true" UnhideWhenUsed="true"
Name="Table Colorful 2"/>
<w:LsdException Locked="false" SemiHidden="true" UnhideWhenUsed="true"
Name="Table Colorful 3"/>
<w:LsdException Locked="false" SemiHidden="true" UnhideWhenUsed="true"
Name="Table Columns 1"/>
<w:LsdException Locked="false" SemiHidden="true" UnhideWhenUsed="true"
Name="Table Columns 2"/>
<w:LsdException Locked="false" SemiHidden="true" UnhideWhenUsed="true"
Name="Table Columns 3"/>
<w:LsdException Locked="false" SemiHidden="true" UnhideWhenUsed="true"
Name="Table Columns 4"/>
<w:LsdException Locked="false" SemiHidden="true" UnhideWhenUsed="true"
Name="Table Columns 5"/>
<w:LsdException Locked="false" SemiHidden="true" UnhideWhenUsed="true"
Name="Table Grid 1"/>
<w:LsdException Locked="false" SemiHidden="true" UnhideWhenUsed="true"
Name="Table Grid 2"/>
<w:LsdException Locked="false" SemiHidden="true" UnhideWhenUsed="true"
Name="Table Grid 3"/>
<w:LsdException Locked="false" SemiHidden="true" UnhideWhenUsed="true"
Name="Table Grid 4"/>
<w:LsdException Locked="false" SemiHidden="true" UnhideWhenUsed="true"
Name="Table Grid 5"/>
<w:LsdException Locked="false" SemiHidden="true" UnhideWhenUsed="true"
Name="Table Grid 6"/>
<w:LsdException Locked="false" SemiHidden="true" UnhideWhenUsed="true"
Name="Table Grid 7"/>
<w:LsdException Locked="false" SemiHidden="true" UnhideWhenUsed="true"
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<w:LsdException Locked="false" SemiHidden="true" UnhideWhenUsed="true"
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<w:LsdException Locked="false" SemiHidden="true" UnhideWhenUsed="true"
Name="Table List 2"/>
<w:LsdException Locked="false" SemiHidden="true" UnhideWhenUsed="true"
Name="Table List 3"/>
<w:LsdException Locked="false" SemiHidden="true" UnhideWhenUsed="true"
Name="Table List 4"/>
<w:LsdException Locked="false" SemiHidden="true" UnhideWhenUsed="true"
Name="Table List 5"/>
<w:LsdException Locked="false" SemiHidden="true" UnhideWhenUsed="true"
Name="Table List 6"/>
<w:LsdException Locked="false" SemiHidden="true" UnhideWhenUsed="true"
Name="Table List 7"/>
<w:LsdException Locked="false" SemiHidden="true" UnhideWhenUsed="true"
Name="Table List 8"/>
<w:LsdException Locked="false" SemiHidden="true" UnhideWhenUsed="true"
Name="Table 3D effects 1"/>
<w:LsdException Locked="false" SemiHidden="true" UnhideWhenUsed="true"
Name="Table 3D effects 2"/>
<w:LsdException Locked="false" SemiHidden="true" UnhideWhenUsed="true"
Name="Table 3D effects 3"/>
<w:LsdException Locked="false" SemiHidden="true" UnhideWhenUsed="true"
Name="Table Contemporary"/>
<w:LsdException Locked="false" SemiHidden="true" UnhideWhenUsed="true"
Name="Table Elegant"/>
<w:LsdException Locked="false" SemiHidden="true" UnhideWhenUsed="true"
Name="Table Professional"/>
<w:LsdException Locked="false" SemiHidden="true" UnhideWhenUsed="true"
Name="Table Subtle 1"/>
<w:LsdException Locked="false" SemiHidden="true" UnhideWhenUsed="true"
Name="Table Subtle 2"/>
<w:LsdException Locked="false" SemiHidden="true" UnhideWhenUsed="true"
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<w:LsdException Locked="false" SemiHidden="true" UnhideWhenUsed="true"
Name="Table Web 2"/>
<w:LsdException Locked="false" SemiHidden="true" UnhideWhenUsed="true"
Name="Table Web 3"/>
<w:LsdException Locked="false" SemiHidden="true" UnhideWhenUsed="true"
Name="Balloon Text"/>
<w:LsdException Locked="false" Priority="39" Name="Table Grid"/>
<w:LsdException Locked="false" SemiHidden="true" UnhideWhenUsed="true"
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<w:LsdException Locked="false" SemiHidden="true" UnhideWhenUsed="true"
Name="Note Level 1"/>
<w:LsdException Locked="false" SemiHidden="true" UnhideWhenUsed="true"
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<w:LsdException Locked="false" SemiHidden="true" UnhideWhenUsed="true"
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<w:LsdException Locked="false" SemiHidden="true" UnhideWhenUsed="true"
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<w:LsdException Locked="false" SemiHidden="true" UnhideWhenUsed="true"
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<w:LsdException Locked="false" SemiHidden="true" UnhideWhenUsed="true"
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<w:LsdException Locked="false" SemiHidden="true" UnhideWhenUsed="true"
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<w:LsdException Locked="false" SemiHidden="true" UnhideWhenUsed="true"
Name="Note Level 8"/>
<w:LsdException Locked="false" SemiHidden="true" UnhideWhenUsed="true"
Name="Note Level 9"/>
<w:LsdException Locked="false" SemiHidden="true" Name="Placeholder Text"/>
<w:LsdException Locked="false" Priority="1" QFormat="true" Name="No Spacing"/>
<w:LsdException Locked="false" Priority="60" Name="Light Shading"/>
<w:LsdException Locked="false" Priority="61" Name="Light List"/>
<w:LsdException Locked="false" Priority="62" Name="Light Grid"/>
<w:LsdException Locked="false" Priority="63" Name="Medium Shading 1"/>
<w:LsdException Locked="false" Priority="64" Name="Medium Shading 2"/>
<w:LsdException Locked="false" Priority="65" Name="Medium List 1"/>
<w:LsdException Locked="false" Priority="66" Name="Medium List 2"/>
<w:LsdException Locked="false" Priority="67" Name="Medium Grid 1"/>
<w:LsdException Locked="false" Priority="68" Name="Medium Grid 2"/>
<w:LsdException Locked="false" Priority="69" Name="Medium Grid 3"/>
<w:LsdException Locked="false" Priority="70" Name="Dark List"/>
<w:LsdException Locked="false" Priority="71" Name="Colorful Shading"/>
<w:LsdException Locked="false" Priority="72" Name="Colorful List"/>
<w:LsdException Locked="false" Priority="73" Name="Colorful Grid"/>
<w:LsdException Locked="false" Priority="60" Name="Light Shading Accent 1"/>
<w:LsdException Locked="false" Priority="61" Name="Light List Accent 1"/>
<w:LsdException Locked="false" Priority="62" Name="Light Grid Accent 1"/>
<w:LsdException Locked="false" Priority="63" Name="Medium Shading 1 Accent 1"/>
<w:LsdException Locked="false" Priority="64" Name="Medium Shading 2 Accent 1"/>
<w:LsdException Locked="false" Priority="65" Name="Medium List 1 Accent 1"/>
<w:LsdException Locked="false" SemiHidden="true" Name="Revision"/>
<w:LsdException Locked="false" Priority="34" QFormat="true"
Name="List Paragraph"/>
<w:LsdException Locked="false" Priority="29" QFormat="true" Name="Quote"/>
<w:LsdException Locked="false" Priority="30" QFormat="true"
Name="Intense Quote"/>
<w:LsdException Locked="false" Priority="66" Name="Medium List 2 Accent 1"/>
<w:LsdException Locked="false" Priority="67" Name="Medium Grid 1 Accent 1"/>
<w:LsdException Locked="false" Priority="68" Name="Medium Grid 2 Accent 1"/>
<w:LsdException Locked="false" Priority="69" Name="Medium Grid 3 Accent 1"/>
<w:LsdException Locked="false" Priority="70" Name="Dark List Accent 1"/>
<w:LsdException Locked="false" Priority="71" Name="Colorful Shading Accent 1"/>
<w:LsdException Locked="false" Priority="72" Name="Colorful List Accent 1"/>
<w:LsdException Locked="false" Priority="73" Name="Colorful Grid Accent 1"/>
<w:LsdException Locked="false" Priority="60" Name="Light Shading Accent 2"/>
<w:LsdException Locked="false" Priority="61" Name="Light List Accent 2"/>
<w:LsdException Locked="false" Priority="62" Name="Light Grid Accent 2"/>
<w:LsdException Locked="false" Priority="63" Name="Medium Shading 1 Accent 2"/>
<w:LsdException Locked="false" Priority="64" Name="Medium Shading 2 Accent 2"/>
<w:LsdException Locked="false" Priority="65" Name="Medium List 1 Accent 2"/>
<w:LsdException Locked="false" Priority="66" Name="Medium List 2 Accent 2"/>
<w:LsdException Locked="false" Priority="67" Name="Medium Grid 1 Accent 2"/>
<w:LsdException Locked="false" Priority="68" Name="Medium Grid 2 Accent 2"/>
<w:LsdException Locked="false" Priority="69" Name="Medium Grid 3 Accent 2"/>
<w:LsdException Locked="false" Priority="70" Name="Dark List Accent 2"/>
<w:LsdException Locked="false" Priority="71" Name="Colorful Shading Accent 2"/>
<w:LsdException Locked="false" Priority="72" Name="Colorful List Accent 2"/>
<w:LsdException Locked="false" Priority="73" Name="Colorful Grid Accent 2"/>
<w:LsdException Locked="false" Priority="60" Name="Light Shading Accent 3"/>
<w:LsdException Locked="false" Priority="61" Name="Light List Accent 3"/>
<w:LsdException Locked="false" Priority="62" Name="Light Grid Accent 3"/>
<w:LsdException Locked="false" Priority="63" Name="Medium Shading 1 Accent 3"/>
<w:LsdException Locked="false" Priority="64" Name="Medium Shading 2 Accent 3"/>
<w:LsdException Locked="false" Priority="65" Name="Medium List 1 Accent 3"/>
<w:LsdException Locked="false" Priority="66" Name="Medium List 2 Accent 3"/>
<w:LsdException Locked="false" Priority="67" Name="Medium Grid 1 Accent 3"/>
<w:LsdException Locked="false" Priority="68" Name="Medium Grid 2 Accent 3"/>
<w:LsdException Locked="false" Priority="69" Name="Medium Grid 3 Accent 3"/>
<w:LsdException Locked="false" Priority="70" Name="Dark List Accent 3"/>
<w:LsdException Locked="false" Priority="71" Name="Colorful Shading Accent 3"/>
<w:LsdException Locked="false" Priority="72" Name="Colorful List Accent 3"/>
<w:LsdException Locked="false" Priority="73" Name="Colorful Grid Accent 3"/>
<w:LsdException Locked="false" Priority="60" Name="Light Shading Accent 4"/>
<w:LsdException Locked="false" Priority="61" Name="Light List Accent 4"/>
<w:LsdException Locked="false" Priority="62" Name="Light Grid Accent 4"/>
<w:LsdException Locked="false" Priority="63" Name="Medium Shading 1 Accent 4"/>
<w:LsdException Locked="false" Priority="64" Name="Medium Shading 2 Accent 4"/>
<w:LsdException Locked="false" Priority="65" Name="Medium List 1 Accent 4"/>
<w:LsdException Locked="false" Priority="66" Name="Medium List 2 Accent 4"/>
<w:LsdException Locked="false" Priority="67" Name="Medium Grid 1 Accent 4"/>
<w:LsdException Locked="false" Priority="68" Name="Medium Grid 2 Accent 4"/>
<w:LsdException Locked="false" Priority="69" Name="Medium Grid 3 Accent 4"/>
<w:LsdException Locked="false" Priority="70" Name="Dark List Accent 4"/>
<w:LsdException Locked="false" Priority="71" Name="Colorful Shading Accent 4"/>
<w:LsdException Locked="false" Priority="72" Name="Colorful List Accent 4"/>
<w:LsdException Locked="false" Priority="73" Name="Colorful Grid Accent 4"/>
<w:LsdException Locked="false" Priority="60" Name="Light Shading Accent 5"/>
<w:LsdException Locked="false" Priority="61" Name="Light List Accent 5"/>
<w:LsdException Locked="false" Priority="62" Name="Light Grid Accent 5"/>
<w:LsdException Locked="false" Priority="63" Name="Medium Shading 1 Accent 5"/>
<w:LsdException Locked="false" Priority="64" Name="Medium Shading 2 Accent 5"/>
<w:LsdException Locked="false" Priority="65" Name="Medium List 1 Accent 5"/>
<w:LsdException Locked="false" Priority="66" Name="Medium List 2 Accent 5"/>
<w:LsdException Locked="false" Priority="67" Name="Medium Grid 1 Accent 5"/>
<w:LsdException Locked="false" Priority="68" Name="Medium Grid 2 Accent 5"/>
<w:LsdException Locked="false" Priority="69" Name="Medium Grid 3 Accent 5"/>
<w:LsdException Locked="false" Priority="70" Name="Dark List Accent 5"/>
<w:LsdException Locked="false" Priority="71" Name="Colorful Shading Accent 5"/>
<w:LsdException Locked="false" Priority="72" Name="Colorful List Accent 5"/>
<w:LsdException Locked="false" Priority="73" Name="Colorful Grid Accent 5"/>
<w:LsdException Locked="false" Priority="60" Name="Light Shading Accent 6"/>
<w:LsdException Locked="false" Priority="61" Name="Light List Accent 6"/>
<w:LsdException Locked="false" Priority="62" Name="Light Grid Accent 6"/>
<w:LsdException Locked="false" Priority="63" Name="Medium Shading 1 Accent 6"/>
<w:LsdException Locked="false" Priority="64" Name="Medium Shading 2 Accent 6"/>
<w:LsdException Locked="false" Priority="65" Name="Medium List 1 Accent 6"/>
<w:LsdException Locked="false" Priority="66" Name="Medium List 2 Accent 6"/>
<w:LsdException Locked="false" Priority="67" Name="Medium Grid 1 Accent 6"/>
<w:LsdException Locked="false" Priority="68" Name="Medium Grid 2 Accent 6"/>
<w:LsdException Locked="false" Priority="69" Name="Medium Grid 3 Accent 6"/>
<w:LsdException Locked="false" Priority="70" Name="Dark List Accent 6"/>
<w:LsdException Locked="false" Priority="71" Name="Colorful Shading Accent 6"/>
<w:LsdException Locked="false" Priority="72" Name="Colorful List Accent 6"/>
<w:LsdException Locked="false" Priority="73" Name="Colorful Grid Accent 6"/>
<w:LsdException Locked="false" Priority="19" QFormat="true"
Name="Subtle Emphasis"/>
<w:LsdException Locked="false" Priority="21" QFormat="true"
Name="Intense Emphasis"/>
<w:LsdException Locked="false" Priority="31" QFormat="true"
Name="Subtle Reference"/>
<w:LsdException Locked="false" Priority="32" QFormat="true"
Name="Intense Reference"/>
<w:LsdException Locked="false" Priority="33" QFormat="true" Name="Book Title"/>
<w:LsdException Locked="false" Priority="37" SemiHidden="true"
UnhideWhenUsed="true" Name="Bibliography"/>
<w:LsdException Locked="false" Priority="39" SemiHidden="true"
UnhideWhenUsed="true" QFormat="true" Name="TOC Heading"/>
<w:LsdException Locked="false" Priority="41" Name="Plain Table 1"/>
<w:LsdException Locked="false" Priority="42" Name="Plain Table 2"/>
<w:LsdException Locked="false" Priority="43" Name="Plain Table 3"/>
<w:LsdException Locked="false" Priority="44" Name="Plain Table 4"/>
<w:LsdException Locked="false" Priority="45" Name="Plain Table 5"/>
<w:LsdException Locked="false" Priority="40" Name="Grid Table Light"/>
<w:LsdException Locked="false" Priority="46" Name="Grid Table 1 Light"/>
<w:LsdException Locked="false" Priority="47" Name="Grid Table 2"/>
<w:LsdException Locked="false" Priority="48" Name="Grid Table 3"/>
<w:LsdException Locked="false" Priority="49" Name="Grid Table 4"/>
<w:LsdException Locked="false" Priority="50" Name="Grid Table 5 Dark"/>
<w:LsdException Locked="false" Priority="51" Name="Grid Table 6 Colorful"/>
<w:LsdException Locked="false" Priority="52" Name="Grid Table 7 Colorful"/>
<w:LsdException Locked="false" Priority="46"
Name="Grid Table 1 Light Accent 1"/>
<w:LsdException Locked="false" Priority="47" Name="Grid Table 2 Accent 1"/>
<w:LsdException Locked="false" Priority="48" Name="Grid Table 3 Accent 1"/>
<w:LsdException Locked="false" Priority="49" Name="Grid Table 4 Accent 1"/>
<w:LsdException Locked="false" Priority="50" Name="Grid Table 5 Dark Accent 1"/>
<w:LsdException Locked="false" Priority="51"
Name="Grid Table 6 Colorful Accent 1"/>
<w:LsdException Locked="false" Priority="52"
Name="Grid Table 7 Colorful Accent 1"/>
<w:LsdException Locked="false" Priority="46"
Name="Grid Table 1 Light Accent 2"/>
<w:LsdException Locked="false" Priority="47" Name="Grid Table 2 Accent 2"/>
<w:LsdException Locked="false" Priority="48" Name="Grid Table 3 Accent 2"/>
<w:LsdException Locked="false" Priority="49" Name="Grid Table 4 Accent 2"/>
<w:LsdException Locked="false" Priority="50" Name="Grid Table 5 Dark Accent 2"/>
<w:LsdException Locked="false" Priority="51"
Name="Grid Table 6 Colorful Accent 2"/>
<w:LsdException Locked="false" Priority="52"
Name="Grid Table 7 Colorful Accent 2"/>
<w:LsdException Locked="false" Priority="46"
Name="Grid Table 1 Light Accent 3"/>
<w:LsdException Locked="false" Priority="47" Name="Grid Table 2 Accent 3"/>
<w:LsdException Locked="false" Priority="48" Name="Grid Table 3 Accent 3"/>
<w:LsdException Locked="false" Priority="49" Name="Grid Table 4 Accent 3"/>
<w:LsdException Locked="false" Priority="50" Name="Grid Table 5 Dark Accent 3"/>
<w:LsdException Locked="false" Priority="51"
Name="Grid Table 6 Colorful Accent 3"/>
<w:LsdException Locked="false" Priority="52"
Name="Grid Table 7 Colorful Accent 3"/>
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<span lang="EN-GB" style="font-family: Calibri; mso-ascii-theme-font: minor-latin; mso-hansi-theme-font: minor-latin;">Doron Swade<o:p></o:p></span></div>
</div>
Unknownnoreply@blogger.com1tag:blogger.com,1999:blog-1256203328790934312.post-64139761449353730162016-05-12T05:18:00.001-07:002016-05-12T05:18:23.655-07:00Spring 2016 report to the Computer Conservation Society<div dir="ltr" style="text-align: left;" trbidi="on">
This was presented on May 11 to the <a href="http://www.computerconservationsociety.org/">Computer Conservation Society</a> by Doron Swade.<br />
<br />
<br />
We have been pecking away at Babbage’s original design drawings for some while now and have found with regret that we are unable to reverse engineer a coherent and consistent understanding of the Analytical Engine from the mechanical drawings alone. There are some 300 drawings and some 2200 Notations – descriptions of the mechanisms using Babbage’s language of signs and symbols. There were three phases of design - early, middle, and late.There is overlap between these, there are ad hoc upgrades, and only fragmentary explanation, where there is explanation at all.<br />
<br />
It remains unclear whether any of these three phases is graced by a complete design. This in itself would be unfortunate but not catastrophic as mechanisms can be devised as functional replicas for omissions provided the intended function is fully understood. The immediate problem is that the extent of incompleteness is not clear. The work of the late Allan Bromley in decoding the AE designs in invaluable but he published only a small part of his substantial findings and these are anyway based on only part of the archive. While much is understood about many of the main mechanisms and the general scheme, there remain fundamental aspects control and sequencing that are not yet well understood and have resisted further illumination.<br />
<br />
To achieve a more comprehensive understanding of the designs Tim Robinson in the US is going through the entire Babbage archive (over 7000 manuscript sheets) and producing a cross-referenced searchable data base. The purpose of this is to marshal all known sources so that we have a bounded idea of all relevant material. The intention is to reveal any explanations and/or drawings that Babbage might have left that have not yet come to light.<br />
<br />
A second line of attack is to the 2200 Notations for the AE using the newly acquired knowledge of the Mechanical Notation. Allan Bromley maintained that the Notations were indispensible to his understanding. However he did not publish how he had used the Notations and he was the last to use them as an interpretative tool. The hope here is that the Notations will provide some of the missing information about logical control and moreover give insights into design strategy. In parallel with Tim’s comprehensive data base index I am going through the twenty volumes of Babbage’s ‘Scribbling Books’ identifying all material on the Mechanical Notation – a fast-track way of accessing this specific material.<br />
<br />
Currently the stages envisaged for the project are:<br />
<br />
1. Finalising research of the original design<br />
2. Specifying a viable version<br />
3. Computer modelling and simulation/3D printing<br />
4. Manufacture and construction<br />
<br />
We need more hands to the pumps and have latterly diverted some effort to fundraising. We have a 3-year plan at the end of which we expect have the requisite understanding of the designs, a platform from which to specify a viable version of an AE that is historically authentic, and to have trialled tools for modelling and simulation. The funding proposal includes pulling in requisite expertise including modellers and mechanical engineers.<br />
<br />
In summary, we have had to bite the bullet with the realisation that without a concerted assault on the sources, a fuller understanding of the Engine design will not be forthcoming. We need to understand the intentions of the design well enough to identify missing mechanisms and understand their intended purpose well enough to devise fill-ins that are consistent with Babbage’s design style. Effort is now divided between continued study of the designs and fundraising to ramp up the effort.<br />
<br />
Doron Swade</div>
Unknownnoreply@blogger.com62tag:blogger.com,1999:blog-1256203328790934312.post-20716123672662194622016-05-03T11:00:00.002-07:002016-05-03T11:07:52.719-07:00Winter 2015: Project Report to the Computer Conservation Society<div dir="ltr" style="text-align: left;" trbidi="on">
The following report appeared in the <a href="http://www.computerconservationsociety.org/resurrection/res72.htm">Winter 2015 Resurrection</a>:<br />
<br />
The bicentennial year of Ada Lovelace’s birth falls this year. Preparation for various celebratory events has directed attention to Ada Lovelace’s ‘program’ (1843) to calculate Bernoulli numbers using Charles Babbage’s unbuilt Analytical Engine. A small group including Tim Robinson in the US, Rainer Glaschick in Germany, Bernard Sufrin in the UK (and me) have been collaborating in exploring the ‘program’. Significant progress has been made with many obscurities now illuminated. The study has directed new attention to how the several types of punched card control the internal microprograms on the one hand, and how these functions interface with the user on the other.<br />
<br />
There has been significant archive activity. The major historical source is the Babbage technical archive held by the Science Museum. The Science Museum digitised the archive in 2012 is now preparing to provide open access to the archive. The Analytical Engine project team has been the main user of the digitised archive under special licence. In the course of the project mismatches have been identified between the digitised material and the existing printed index compiled by the late Allan Bromley and published by the Science Museum in 1991. Referencing anomalies, identification of material omitted from digitisation exercise and other structural issues have become evident. Descriptions of these have been compiled and we are working with Science Museum archivists to resolve and correct these ahead of open access release. The work is detailed and, given the volume of material, substantial. Eye-strain is an ongoing hazard.<br />
<br />
This archive work has suggested a new and significant prospect for the role of the Notation in an understanding the designs. One of the difficulties in understanding the designs is the need to reverse engineer logical function from mechanical drawings of mechanisms - this without textual explanation of purpose or intention. The original hope was that the notations, expressed in Babbage’s symbolic descriptive language, would contain a higher-level logical description that would relieve this difficulty. As described in earlier reports the main features of the Notation were decoded from a detailed knowledge of the mechanisms of Difference Engine No.2. The provisional conclusion from that study was that the notations are a description of the mutual physical relationships of mechanical parts and are not an abstraction of a logical description of the Engine’s function. Further, that the mechanical design preceded the notational description. New material found in the archive suggests that while this might be true for Difference Engine No.2 the notations for the Analytical Engine (about 2,700 of these) may indeed embody higher-level logic, control functions for sequencing the punched cards and orchestrating the internal operations that the punched cards control. If so, the notations would provide the explanatory tool we have been looking for and the prospect of this is enough to distract one from the plight of refugees migrants and austerity, even if only briefly.<br />
<br />
<br class="Apple-interchange-newline" />Doron Swade</div>
Unknownnoreply@blogger.com2tag:blogger.com,1999:blog-1256203328790934312.post-37497625731443647732016-05-03T10:07:00.000-07:002016-05-03T11:07:45.551-07:00Further progress as reported to the Computer Conservation Society<div dir="ltr" style="text-align: left;" trbidi="on">
Progress continues decoding Babbage’s Mechanical Notation – the language of signs and symbols Babbage devised to describe the mechanisms of his calculating Engines. There has been a new archival find in manuscript papers Babbage gave to a younger colleague, Harry Wilmot Buxton. The Buxton papers are held by the Museum of the History of Science, Oxford. The papers were known about and some material has been published but last time the papers were viewed predates the focussed interest on the Analytical Engine, and the significance of the material on the Mechanical Notation passed unnoticed. With the kind permission of the archivist, permission was given for a copying rostrum to be used and the relevant material was digitally photographed in situ. The significance of the material is two- fold: it contains Babbage’s efforts to provide generalised rules for annotating his mechanical drawings; secondly, the principles it documents confirms our findings from the earlier exercise in which knowledge of the Difference Engine mechanisms were used to decode the Notations that describe them – this without the benefit of generalised rules of syntax orgrammar. The agreement between the archive and our earlier findings is a satisfying vindication of the decoding method using known mechanisms.<br />
<br />
The Ada Lovelace bicentennial, celebrated this year, has directed attention to the Analytical Engine through the description of the Engine Lovelace published in 1843. Her description of the Engine is in the form of Notes which form a substantial addendum to the account by Luigi Menabrea who wrote up some of Babbage’s lectures on the Analytical Engine Babbage gave in Turin in 1840. The ongoing preparation of celebratory exhibitions, symposia andmedia coverage, has redirected attention to specific features of Lovelace’s description. One such is the use control arrangements between the punched card input and the routing of information between the cards, processor and memory. It appears that there is no form of indexed or relative addressing either of which would be required for the AE to execute the example given by Lovelace - the calculation of Bernoulli numbers. It is far from clear how the Engine executes its control functions and there are several ongoing collaborative conversations between scholars and historians analysing the issue stimulated by the extended interest in Lovelace’s work. The lesson we have taken is that much as is known about the principles of the AE, there is much that is not understood at the fundamental level of internal control and such understanding is a prerequisite of any construction, physical or virtual.<br />
<br />
Doron Swade</div>
Unknownnoreply@blogger.com0tag:blogger.com,1999:blog-1256203328790934312.post-86895297120812044882016-05-03T10:04:00.000-07:002016-05-03T11:07:59.366-07:00Autumn 2015: Progress Report for the Computer Conservation Society<div dir="ltr" style="text-align: left;" trbidi="on">
The following appear in the <a href="http://www.computerconservationsociety.org/resurrection/res71.htm">Autumn 2015 Resurrection</a><br />
<br />
There has been a new archival find in manuscript papers Babbage gave to a younger colleague, Harry Wilmot Buxton. The Buxton papers are held by the Museum of the History of Science, Oxford. The papers were known about and some material has been published but last time the papers were viewed predates the focussed interest on the Analytical Engine, and the significance of the material on the Mechanical Notation passed unnoticed. With the kind permission of the archivist, permission was given for a copying rostrum to be used and the relevant material was digitally photographed in situ. The significance of the material is twofold: it contains Babbage’s efforts to provide generalised rules for annotating his mechanical drawings; secondly, the principles it documents confirm our findings from the earlier exercise in which knowledge of the Difference Engine mechanisms were used to decode the Notations that describe them — this without the benefit of an generalised rules of syntax or grammar. The agreement between the archive and our earlier findings is a satisfying vindication of the decoding method using known mechanisms.<br />
<br />
The Ada Lovelace bicentennial, celebrated this year, has directed attention to the Analytical Engine through the description of the Engine which Lovelace published in 1843. Her description of the Engine is in the form of Notes which form a substantial addendum to the account by Luigi Menabrea who wrote up some of Babbage’s lectures on the Analytical Engine Babbage gave in Turin in 1840. The ongoing preparation of celebratory exhibitions, symposia and media coverage, has redirected attention to specific features of Lovelace’s description. One such is the use control arrangements between the punched card input and the routing of information between the cards, processor and memory. There is evidently no form of indexed or relative addressing either of which would be required for the AE to execute the example given by Lovelace - the automatic calculation of Bernoulli numbers. It is far from clear how the Engine executes its control functions and there are several ongoing collaborative conversations between scholars and historians analysing the issue stimulated by the extended interest in Lovelace’s work. The lesson we have taken is that much as is known about the principles of the AE, there is much that is not understood at the fundamental level of internal control and such understanding is a prerequisite of any construction, physical or virtual.<br />
<br />
<br class="Apple-interchange-newline" />Doron Swade<br />
<br /></div>
Unknownnoreply@blogger.com0tag:blogger.com,1999:blog-1256203328790934312.post-74344185020357699432015-03-19T15:54:00.001-07:002015-03-19T15:57:36.064-07:00Progress on understanding Babbage's Mechanical Notation<div dir="ltr" style="text-align: left;" trbidi="on">
A previous blog post explained Babbage's <a href="http://blog.plan28.org/2014/11/babbages-language-of-thought.html">mechanical notation</a> which is key to understanding and building the Analytical Engine. This blog post gives a quick update on work done.<br />
<br />
"Project Report to Computer Conservation Society Committee for Meeting Thursday 19 March 2015<br />
<br />
Analytical Engine<br />
<br />
Major progress has been made decoding Trains diagrams – these are the ‘flow charts’ in Charles Babbage’s notational language. There are some 90 separate symbols in the alphabet denoting (a) the form of the part (lever, gear, pendulum, bar, rack, pinion . . .) and (b) type of motion (circular, linear, reciprocating . . . ). The method we are using involves examining the symbols in the Train that describe a particular mechanism in the Engine (addition, carriage, warning, locking . . ) and from an existing knowledge of the function of the mechanism, infer the usage of the symbols used to describe each part. Progress made to date encourages us to believe that the whole language will yield to this method. The version of the notation being used for this process was formulated in 1851 which post-dates both the major work on the Analytical Engine and the complete design for Difference Engine No. 2 and is therefore likely to be representative of the notation conventions as used for both these engines. Once this decoding exercise is complete attention will turn to the historical evolution of the Notation from 1822 through to 1871 i.e. an exploration of how the notational language was expanded and developed to describe mechanisms of increasing complexity.<br />
<br />
The study of the notation is part of the Notions and Notations project funded by the Leverhulme Trust. There has been rapid progress in the two other major elements of this project: software implementation of the Notation, and an exploration of alternative designs. We have defined an ASCII-text language called FORTRAC15 which captures and expresses Babbage’s hand-written notations. The name FORTRAC derives from the three descriptive elements of Babbage's Notation: Forms are un-dimensioned engineering diagrams and show the shape of parts and their relationship to one another; Trains show the chain of cause and effect within a mechanism; and Cycles show timing and phasing relationships of moving parts. Any resemblance between the name FORTRAC and that of other early formal languages is entirely intentional.<br />
<br />
Significant software tooling for FORTRAC is underway. We envisage inter-linking between graphical icons that are the notational symbols, 3D animations of parts, and FORTRAC15 textual descriptions. As a first stage we are building a tool that allows JPEG images of the notations to be annotated with FORTAC15 textual terms. We are now using this tool to capture all the Difference Engine No. 2 notations in machine readable form. This process has exposed omissions, anomalies and ambiguities in the original notational description of the Engine and clarified the scope of what is describable in the notational language. Some unexpected features have also been thrown up including examples of highly nuanced use. We are also designing and constructing 'alternate’ Difference Engines making use of modern rapid prototyping technologies. A prototype digit-serial engine that would have around 15% of the throughput of DE2 has been partially demonstrated using sintered-nylon 3D printing and some stock gearing. All parts could have been machined or cast using 1830's technologies. As of March 2015, one quarter of a complete machine has been constructed.<br />
<br />
The significance of this to the Analytical Engine project is partly to address the question of ‘how else might Babbage have done this using technology available to him at the time?’ The architecture of the Analytical Engine (1834-1871) conforms identifiably to Von Neumann’s in all major logical respects. This raises the question of whether this architecture contains something fundamental about logical implementation of general purpose digital computing.<br />
<br />
The ‘alternative Difference Engine’ is a modern exploration of necessary uniqueness in physical implementation and will inform the analysis of the Analytical Engine designs.<br />
<br />
Doron Swade<br />
<br />
11 March 2015"</div>
Unknownnoreply@blogger.com6