Talk:Von Neumann architecture

Removing redundant diagram

There are two diagrams, both with the caption "Von Neumann architecture scheme", that are almost identical. The only real difference, other than color, is that the input and output devices are shown connecting directly to the accumulator in the arithmetic logic unit in the second example, rather than to the unit as a whole. I believe that is less accurate. Hence, I am removing the reference to the second diagram. - AlanUS (talk) 20:53, 7 January 2016 (UTC)

Agreed. Andy Dingley (talk) 22:44, 7 January 2016 (UTC)

The one you left in was a newer addition to the page; you removed the older one. I consider the one you left there to be better than the one you removed, so I think you did the right thing here. Guy Harris (talk) 22:55, 7 January 2016 (UTC)

an original work of Von Neumann

IMHO the book or article, where Von Neumann architecture was introduced should be mentioned (with a link, if possible) —Preceding unsigned comment added by 85.140.22.47 (talk • contribs) 03:08, 18 April 2005

There it is... You could have done it yourself, it only took two quick Google searches (one on "von neumann architecture eniac" to find the title and one on the title to find a PDF of the paper itself). -- RTC 21:54, 18 Apr 2005 (UTC)

Earliest dates for stored program computers

If anyone has more information for the dates about the earlies stored program computers, please include it. --Bubba73 05:49, 4 Jun 2005 (UTC)

External links modified

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• Corrected formatting/usage for http://aws.linnbenton.edu/cs271c/markgrj/
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• Added archive https://web.archive.org/web/20170202001232/http://patft1.uspto.gov/netacgi/nph-Parser?Sect1=PTO1&Sect2=HITOFF&d=PALL&p=1&u=%2Fnetahtml%2FPTO%2Fsrchnum.htm&r=1&f=G&l=50&s1=2636672.PN.&OS=PN%2F2636672&RS=PN%2F2636672 to http://patft1.uspto.gov/netacgi/nph-Parser?Sect1=PTO1&Sect2=HITOFF&d=PALL&p=1&u=%2Fnetahtml%2FPTO%2Fsrchnum.htm&r=1&f=G&l=50&s1=2636672.PN.&OS=PN%2F2636672&RS=PN%2F2636672

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Works, but it's better to use the patent templates, so I did that for the patent reference. Guy Harris (talk) 20:07, 11 December 2017 (UTC)

Recent edits

Recently, this article has been edited by Camion (talk · contribs · deleted contribs · logs · filter log · block user · block log). Camion is a new Wikipedia editor, and clearly wants to improve the encyclopedia, so we want to encourage him/her -- we need more good editors.

Alas, Camion's first edits have some problems. Nowhere near as bad as the garbage I was putting out when I first started editing Wikipedia in 2006 (I edited as an IP from January to June, so thankfully my worst edits are hard to find in the history), but still not good.

Again, I do not want to discourage Cameron from learning more about Wikipedia and becoming a valued editor, but in particular, Cameron first changed

Self-modifying code has largely fallen out of favor, since it is usually hard to understand and debug, as well as being inefficient under modern processor pipelining and caching schemes.

to

Self-modifying code has largely fallen out of favor (in the sens "is not recommended"), since it is usually hard to understand and debug, as well as being inefficient under modern processor pipelining and caching schemes. However, it can remain used to compress the code (and uncompress it as the time of loading, or to obfuscate it in order to protect anti piracy mechanisms against reverse engineering.

With the edit summary "self modifying code can uncompress it or protect it against reverse engineering"[1]

I saw several problems with this which I will detail below, but at the time I picked one problem and reverted with the edit summary "Not self-modifying. The code that does the compression is separate from the code that gets uncompressed."[2]

This is based upon the fact that self-modifying code that decompresses itself is almost unknown, even if you go back to when authors tried (and failed) to use it for Commodore 64 and Apple ][ copy protection.

A couple of days later, Camion reintroduced his edit with a modification:

Self-modifying code has largely fallen out of favor (in the sens "is not recommended"), since it is usually hard to understand and debug, as well as being inefficient under modern processor pipelining and caching schemes. However, it can remain used to obfuscate it in order to protect anti piracy mechanisms against reverse engineering."

with the edit summary "correction, then:[3]

There are still a few problems with this edit.

• The first problem is easy to correct, and if it was the only problem I would have simply fixed it The original edit had a "(" without a matching ")" and a spelling error ("sens" instead of "sense"). Camion needs to click on "preview" and check his spelling and grammar before clicking on "publish page".

• "Fallen out of favor" works just fine by itself. There is no need to explain what it means, furthermore, it didn't fall out of favor because it isn't recommended (which it isn't) but because as compilers improved and microprocessors got memory protection, self modifying code simply would not compile and run.

• "to obfuscate it in order to protect anti piracy mechanisms against reverse engineering." is correct as far as it goes, (but a bit awkwardly worded), but fails to mention that this was pretty much only done in the days when people were writing hand-assembled code for thy 8088, 6502, and Z80. By the time the first Pentium came out, self modifying code was pretty much abandoned by everybody. It never really worked anyway -- to this day the most clever copy protection is usually broken within hours. On the PC side of things, different techniques are now used, with mixed results. See Digital Rights Management. On the microcontroller side of things, the smart developer who wants to protect ARM Cortex code uses a chip with TrustZone security. Other chips have fuses that prevent a third party from accessing code memory.

Now I could insert a paragraph that explains some or all of this, But I don't see any real benefit to the reader whon wants to know about the Von Neumann architecture.

Because of all of this, I am once again reverting the edit. I hate to do this to a new editor, but the edit does not meet our quality standards. --Guy Macon (talk) 13:31, 26 October 2018 (UTC)

I'm not a new contributor at all, but I'm sorry about the fact that English is not my mother tongue. By the way, about the code obfuscation, I wasn't thinking that much about anti-copy protection but more about protocol protection like in Skype which is really tricky to reverse engineer and was never cracked in hours. -- Camion (talk) 06:35, 27 October 2018 (UTC)