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<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D">Great questions. You have spotted the main differences between community code projects and managed/professional code projects.<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D"><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D">Ideally, the requirements, primary sources, and any deviant behavior from the primary sources should be documented in the source code base. However, this depends
upon the diligence and understanding of the coders in an open source community model. The best answer is “coders try to document what seems important at the time, unless it appears obvious [to them]”.<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D"><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D">However, one of the main problems with “completing” the source documentation in this way is that most of the deviant behaviors are found experimentally. It
is then difficult for the code maintainer to document the deviant (undocumented) behavior, only that the patch “works”. And thus “lore” is born.<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D"><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D">We could potentially solve some of the source code quality with a source code template, but practically, coders copy an existing source code file that is similar
and modify it. So we’d really need to upgrade the existing modules to the “source code standard” before being able to ensure that future coders do it the right way. Or else have the project introduce the additional management overhead of explicitly defined
coding standards, checklists, and gatekeeper code reviews. :-) Both are a lot of work, so in community projects source code improvement tends to happen with slow code evolution. Volunteers for source code improvement are always welcome.<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D"><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D">Hardware/software interactions are never ending issues in hardware simulation, primary sources, and OS use of the real and simulated hardware. Bob Supnik has
an excellent series of papers discussing many of these discovered hardware/software interaction issues on the SIMH papers page.<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D"><a href="http://simh.trailing-edge.com/papers.html">http://simh.trailing-edge.com/papers.html</a><o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D"><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D">Dave<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D"><o:p> </o:p></span></p>
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<p class="MsoNormal"><b><span style="font-size:10.0pt;font-family:"Tahoma","sans-serif"">From:</span></b><span style="font-size:10.0pt;font-family:"Tahoma","sans-serif""> Simh [mailto:simh-bounces@trailing-edge.com]
<b>On Behalf Of </b>Armistead, Jason BIS<br>
<b>Sent:</b> Tuesday, January 05, 2016 10:13 AM<br>
<b>To:</b> simh@trailing-edge.com<br>
<b>Subject:</b> EXT :[Simh] The minutiae of hardware/software interactions affecting SIMH<o:p></o:p></span></p>
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<p class="MsoNormal"><o:p> </o:p></p>
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<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif"">On the topic of Configuring DMC11 Devices, while discussing wait delays Mark Pizzolato recently wrote:<o:p></o:p></span></p>
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<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif""> <o:p></o:p></span></p>
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<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif"">> Sounds reasonable. I've got to see if I can find the reason the delay was initially added and make sure a change like this is compatible.<o:p></o:p></span></p>
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<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif""> <o:p></o:p></span></p>
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<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif"">What is the “SIMH strategy” for documenting such requirements ? i.e. where does this behavior get called out in the source code (or elsewhere) in a way that will allow future
generations of SIMH users and maintainers to understand “why things are the way they are” or “why things need to be the way they are” ?<o:p></o:p></span></p>
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<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif""> <o:p></o:p></span></p>
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<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif"">There is one reference to the DDCMP protocol manual in the source of pdp11_dmc.c, but that’s about it. Should references to other documents be added ?<o:p></o:p></span></p>
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<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif""> <o:p></o:p></span></p>
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<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif"">Reconstructing and understanding history is easy when people familiar with the subject matter (especially those who lived it, in this case, at DEC) are still around to ask,
but gets progressively harder as years go by without leaving a good trail of “breadcrumbs” for others to follow.<o:p></o:p></span></p>
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<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif""> <o:p></o:p></span></p>
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<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif"">PS: I am constantly amazed at the sheer volume of knowledge and resourcefulness that contributors to this list have, which is one of the reasons I’d love to see as much of
it preserved directly in the SIMH code base !!!<o:p></o:p></span></p>
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<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif""> <o:p></o:p></span></p>
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<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif""> <o:p></o:p></span></p>
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<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif"">Jason<o:p></o:p></span></p>
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<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif""> <o:p></o:p></span></p>
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