When TLB is filled up, older addresses are overwritten. Just like CPU cache, the replacement policy is a potentially complex operation, but a simple and reasonable heuristic is to remove the least recently used entry (LRU).
With LRU, starting from state:adding
valid linear physical
----- ------ --------
> 1 00003 00005
1 00007 00009
1 00009 00001
1 0000B 00003
0000D -> 0000A
would give: valid linear physical
----- ------ --------
1 0000D 0000A
> 1 00007 00009
1 00009 00001
1 0000B 00003
Information about ARM paging can be found at: cirosantilli.com/linux-kernel-module-cheat#arm-paging
The other major university in the Bay Area (and basically in California itself) besides a few University of California places.
The heart of Silicon Valley.
Teachers appear to own it, just allowing perpetual non exclusive rights to university: www.admin.cam.ac.uk/univ/so/pdfs/2022/ordinance13.pdf
30. In relation to teaching materials prepared by a University staff member for use in the teaching primarily of the University’s students, unless the Faculty Board or other body responsible for teaching has agreed explicitly to the contrary, the University shall have a non-exclusive, royalty-free, perpetual license to use the material for teaching in the University.
Year 2 of the mathematics course of the University of Oxford by
Ciro Santilli 37 Updated 2025-07-16
en.bitcoin.it/wiki/Jercos mentions:www.bitcoinwhoswho.com/jercosinterview is the source. Persumably the contact was initiated via the private messaging feature of the Bitcoin Forum.
According to jercos the transaction was finalized over IRC chats. Jercos was 18 at the time of the transaction.
Bibliography:
en.bitcoin.it/wiki/Jercos
en.bitcoin.it/wiki/Jercos
This section is about partial implementations that are only able to read the blocks, ususally coming from Bitcoin Core, to interpret the data:
Cool data embedded in the Bitcoin blockchain Len Sassaman tribute by
Ciro Santilli 37 Updated 2025-07-16
Tribute to computer security researcher Len Sassaman, who killed himself on 2011-07-03, starting with an ASCII art portrait followed by text.
Because it comes so early in the blockchain, and because it is the first ASCII art on the blochain as far as we can see, and because is so well done, this is by far the most visible ASCII art of the Bitcoin blockchain.
Present at tx 930a2114cdaa86e1fac46d15c74e81c09eee1d4150ff9d48e76cb0697d8e1d72. It does not show well on Bitcoin Inscription Indexer however with rationale described at: github.com/cirosantilli/bitcoin-inscription-indexer/tree/3f53e152ec9bb0d070dbcb8f9249d92f89effa70#smart-newline-joining
But it can be seen at on bitcoinStrings.com at: bitcoinstrings.com/blk00003.txt.
Transaction: www.blockchain.com/btc/tx/930a2114cdaa86e1fac46d15c74e81c09eee1d4150ff9d48e76cb0697d8e1d72 from 2011-07-30, a few weeks after the suicide.
Discussion: bitcoin.stackexchange.com/questions/3370/in-which-block-was-len-sassaman-memorialised/101276#101276
Created by famous computer security researcher Dan Kaminsky and Travis Goodspeed, presumably this other security researcher, evidence:
- signature on the tribute
- the art is highlighted at Video 1. "Black OPS of TCP/IP by Dan Kaminsky (2011)", which happened very few days after the art was uploaded to the blockchain, thus making it exceedingly unlikely that someone else could have done it
"Bernanke" is a reference to Ben Bernanke, who was one of the economists in power in the US Government during the financial crisis of 2007-2008, and much criticized by some, as shown for example in the documentary Inside Job (2010). As hinted in the Genesis block message, the United States Government bailed out many big banks that were going to go bankrupt with taxpayer money, even though it was precisly those banks that had started the crisis through their reckless investment, thus violating principles of the free market and business accountability. This was one of the motivations for the creation Bitcoin, which could reduce government power over economic policy.
It is worth mentioning that there do exist some slightly earlier "artistic" inscriptions in the form Punycode inscription in the Namecoin blockchain, but as far as we've seen, the are all trivial compared to
BitLen
in terms of artistic value/size.---BEGIN TRIBUTE---
#./BitLen
:::::::::::::::::::
:::::::.::.::.:.:::
:.: :.' ' ' ' ' : :
:.:'' ,,xiW,"4x, ''
: ,dWWWXXXXi,4WX,
' dWWWXXX7" `X,
lWWWXX7 __ _ X
:WWWXX7 ,xXX7' "^^X
lWWWX7, _.+,, _.+.,
:WWW7,. `^"-" ,^-'
WW",X: X,
"7^^Xl. _(_x7'
l ( :X: __ _
`. " XX ,xxWWWWX7
)X- "" 4X" .___.
,W X :Xi _,,_
WW X 4XiyXWWXd
"" ,, 4XWWWWXX
, R7X, "^447^
R, "4RXk, _, ,
TWk "4RXXi, X',x
lTWk, "4RRR7' 4 XH
:lWWWk, ^" `4
::TTXWWi,_ Xll :..
=-=-=-=-=-=-=-=-=-=
LEN "rabbi" SASSAMA
1980-2011
Len was our friend.
A brilliant mind,
a kind soul, and
a devious schemer;
husband to Meredith
brother to Calvin,
son to Jim and
Dana Hartshorn,
coauthor and
cofounder and
Shmoo and so much
more. We dedicate
this silly hack to
Len, who would have
found it absolutely
hilarious.
--Dan Kaminsky,
Travis Goodspeed
P.S. My apologies,
BitCoin people. He
also would have
LOL'd at BitCoin's
new dependency upon
ASCII BERNANKE
:'::.:::::.:::.::.:
: :.: ' ' ' ' : :':
:.: _.__ '.:
: _,^" "^x, :
' x7' `4,
XX7 4XX
XX XX
Xl ,xxx, ,xxx,XX
( ' _,+o, | ,o+,"
4 "-^' X "^-'" 7
l, ( )) ,X
:Xx,_ ,xXXXxx,_,XX
4XXiX'-___-`XXXX'
4XXi,_ _iXX7'
, `4XXXXXXXXX^ _,
Xx, ""^^^XX7,xX
W,"4WWx,_ _,XxWWX7'
Xwi, "4WW7""4WW7',W
TXXWw, ^7 Xk 47 ,WH
:TXXXWw,_ "), ,wWT:
::TTXXWWW lXl WWT:
----END TRIBUTE----
Code 1.
Len Sassaman tribute
. Official portrait of Ben Bernanke (2008)
Source. Reference image from Wikipedia for the ASCII art.Black OPS of TCP/IP by Dan Kaminsky (2011)
Source. Presented at the BlackHat 2011 conference. Dan unveils the Len memorial at the given timestamp around 8:41. The presentation was done on 2011-08-03 or 04, so very few days after the upload to the blockchain.From the JSON transaction we understand the encoding format:So it is really encoded one line at a time in the
"out":[
{
"spent":false,
"tx_index":0,
"type":0,
"addr":"1CqKQ2EqUscMkeYRFMmgepNGtfKynXzKW7",
"value":1000000,
"n":0,
"script":"76a91481ccb4ee682bc1da3bda70176b7ccc616a6ba9da88ac"
},
{
"spent":false,
"tx_index":0,
"type":0,
"addr":"157sXa7duStAvq3dPLWe7J449sgh47eHzw",
"value":1000000,
"n":1,
"script":"76a9142d2d2d424547494e20545249425554452d2d2d2088ac"
},
...
{
"spent":false,
"tx_index":0,
"type":0,
"addr":"157sXYpjvAyEJ6TdVFaVzmoETAQnHB6FGU",
"value":1000000,
"n":77,
"script":"76a9142d2d2d2d454e4420545249425554452d2d2d2d2088ac"
}
script
of the transaction outputs.Video "The Biggest Ideas in the Universe | 17. Matter by Sean Carroll (2020)" at youtu.be/dQWn9NzvX4s?t=3707 says that no one has ever been able to come up with an intuitive reason for the proof.
The first currently known instance is as a link right during the prayer wars on block 142573 (2011-08-25) as the miner message:which redirects to www.youtube.com/watch?v=mGDuExhS6Nw&blockchain
Militant atheists, bit.ly/naNhG2 -- happy now?"
Around block block 246k (e.g. 27b7c526489dac8245747fa1c425a2e3eb07dea57b294eb4ae583fec9b859fcf, 2013-10-17) we note several transactions starting with a XML format followed by lyrics also base64 encoded as part of the XML metadata. Hidden surprises in the Bitcoin blockchain by Ken Shirriff (2014) was not able to identify the exact format either. At twitter.com/EMBII4U/status/1655831533750562816 EMBII mentions that this was part of an upload test.
<CG SZ="1156"><MG>...
the first one being 0b4efe49ea1454020c4d51a163a93f726a20cd75ad50bb9ed0f4623c141a8008 As mentioned not very clearly at www.righto.com/2014/02/ascii-bernanke-wikileaks-photographs.html#ref12 the content of the first <MG><payload></MG>
is a Base64 encoded stringCatagory: Poetry
Title: Never Gonna Give You Up
Performer: Rick Astley
Writer: Mike Stock, Matt Aitken, Pete Waterman
Label: RCA Records
tx d29c9c0e8e4d2a9790922af73f0b8d51f0bd4bb19940d9cf910ead8fbe85bc9b (2013-11-13) contains a plaintext Rickroll lyric in an output script via OP_RETURN.
tx 15b11e8d4e5b9425f024b381ba0cb7a54a35e52389bb4855f505772ce685b39c (2014-06-24): starting from this transaction, the lyrics were inscribed several times via input scripts. Then again:They were mega obnoxious!!! Who does this kind of crap for more than one year!!!
- 8bb9db70e24202fdfd0e48b57a11a407e6c8c0e76d879634b801b4345b8810b2
- b881afa519804a3c93a3c99481517ca8ae070b84c04e8e7a2bfb808e043f9771
- 70c8405bd0ec10bea49b78a819dfbf46c1082e7e620588f9da65a90b71e52bbd
- fc4e382793757858bec4b87527caa4bf2e6f71bb2f5a77bb41a45ddb9ed9d409
- f011e71b711aa54a0c824244fff83fb8b1e1921804624fa0523a6e61612b7f6f
- a8691cdbca5b82e4e48812e48b7a09e4757801fd3909a09975de957d1bfb52dc
- d8946aa464be464674bba6d15729d75572ec75dda49fe7ff0ede1a25ca054941
- d02864cd57c9d041dbd9d6f24327f347b92697a8bc3c86cdf8b738063c6ad002
- 9b78962d840f1ff681e5042264e4d0359cda98ce49d97569df14ce956622b966
- 7bdc22fb35f0a8eb6241782a306a8904fb6f793126ff106a04a96f9f223cb8e1
- e24a4085c54a6362e615f8eab758c12d80e488b73757e6d2b8ab6bfc8be7007e
- 4257f4980955d8376ee1c6bccb4396da726e4ae13d758e47dc4e0775019723f5
- a09b49e9374d43386a6a986944e3dcf515c7e1c38324836df5333b8adbe57797
- 03096688dbb874f7c571691e4241a298284bf4184be339b148f1b48f383a1d7c
- 62f8b228b6126354736d36d9f3b91882bb81eca7702b74fba6471abc7db96a03 (2015-09-30)
This is opposed to messages that may be left by non miners during transactions.
Miner messages are therefore of course much harder to control on established blockchains, as they basically require consensus in a mining pool to set. Most of them are just ads for the mining pool itself.
Early electron diffraction experiment from 1927 that drastically confirmed the matter wave hypothesis.
Pinned article: Introduction to the OurBigBook Project
Welcome to the OurBigBook Project! Our goal is to create the perfect publishing platform for STEM subjects, and get university-level students to write the best free STEM tutorials ever.
Everyone is welcome to create an account and play with the site: ourbigbook.com/go/register. We belive that students themselves can write amazing tutorials, but teachers are welcome too. You can write about anything you want, it doesn't have to be STEM or even educational. Silly test content is very welcome and you won't be penalized in any way. Just keep it legal!
Intro to OurBigBook
. Source. We have two killer features:
- topics: topics group articles by different users with the same title, e.g. here is the topic for the "Fundamental Theorem of Calculus" ourbigbook.com/go/topic/fundamental-theorem-of-calculusArticles of different users are sorted by upvote within each article page. This feature is a bit like:
- a Wikipedia where each user can have their own version of each article
- a Q&A website like Stack Overflow, where multiple people can give their views on a given topic, and the best ones are sorted by upvote. Except you don't need to wait for someone to ask first, and any topic goes, no matter how narrow or broad
This feature makes it possible for readers to find better explanations of any topic created by other writers. And it allows writers to create an explanation in a place that readers might actually find it.Figure 1. Screenshot of the "Derivative" topic page. View it live at: ourbigbook.com/go/topic/derivativeVideo 2. OurBigBook Web topics demo. Source. - local editing: you can store all your personal knowledge base content locally in a plaintext markup format that can be edited locally and published either:This way you can be sure that even if OurBigBook.com were to go down one day (which we have no plans to do as it is quite cheap to host!), your content will still be perfectly readable as a static site.
- to OurBigBook.com to get awesome multi-user features like topics and likes
- as HTML files to a static website, which you can host yourself for free on many external providers like GitHub Pages, and remain in full control
Figure 2. You can publish local OurBigBook lightweight markup files to either OurBigBook.com or as a static website.Figure 3. Visual Studio Code extension installation.Figure 5. . You can also edit articles on the Web editor without installing anything locally. Video 3. Edit locally and publish demo. Source. This shows editing OurBigBook Markup and publishing it using the Visual Studio Code extension. - Infinitely deep tables of contents:
All our software is open source and hosted at: github.com/ourbigbook/ourbigbook
Further documentation can be found at: docs.ourbigbook.com
Feel free to reach our to us for any help or suggestions: docs.ourbigbook.com/#contact