2017-11-24

Intel's lack of documentation stalled MINIX

11.21: news.cyb/adds/doc/Intel's lack of documentation stalled MINIX:
. in an IEEE Computer interview,
[ieeeComputerSociety 2014]
Tanenbaum revealed he designed MINIX when
AT&T closed the source for Unix Version 7
and they could no longer use it
when teaching about the design of an OS.
. but it kept crashing until he heard a rumor
(nothing in the documentation mentioned it)
that the Intel chip when overheating
was causing an interrupt 15.
If his student Robert hadn't revealed the interrupt,
"there would have been no MINIX" he said.

2017-11-23

common core math's subtraction

10.20: web.math/common core math/has new subtraction:
businessinsider:
. the new way is realizing a subtraction problem
is asking you to measure the distance between 2 numbers;
You do that, in turn, by measuring the distance between
landmarks (easy, round numbers).

phys.org 2015:
we all do arithmetic like this in our heads all the time.
Say you are buying a scone at a bakery for breakfast
and the total price is US$2.60.
You hand the cashier a $10 bill. How much change do you get?
Now, you do not perform the standard algorithm in your head.
You first note that you'd need another
40 cents to get to the next dollar, making $3,
and then you'd need $7 to get up to $10,
so your change is $7.40.

called the counting up subtraction method.
from the smaller number
count up to the nearest 10, 100, etc;
to that add the largest number's smaller digits.

2017-10-25

I, robot (2004)

10.24: tv.adds/robotics/I, robot (2004):
summary:
. the movie "I, robot" had me realizing
how complicated good programming is.
[full synopsis]

2017-08-08

Dr. Daniel Julius Bernstein

7.25: web.cs/sec/Dr. Daniel Julius Bernstein:
. Dr. Daniel Julius Bernstein
is an authority on computer security;
he's a big fan of extreme sandboxing
(where the app is cooperative)
and safe programming languages.
djb's main pagehis papers
(and who they are cited by).

2017-03-01

git uses SHA-1 deprecated by NIST in 2011

2.25: news.cyb/dev/sec/git uses SHA-1 deprecated by NIST in 2011:
3.1: summary:
. git allows teams to concurrently work on software;
it uses SHA-1 hashing of versions,
to tell when files of a version have been modified
to help it merge versions of the software.
. SHA-1 has been cracked so you can modify a file
and yet have it result in the same SHA-1 hash,
thereby hiding the fact that it has been modified.
. the leader of git would like to replace SHA-1
with a more secure hash using more bits,
but would like to use a truncated version of that hash
so that git would only have to store and compare
the same number of bits as SHA-1.
. git is assumed by the leader of git, Linus Torvalds,
to be less vulnerable to the SHA-1 attack
because it includes not just the hash of a file
but also its size;
he gives no proof other than appeal to intuition:
can you imagine a way to add working malware to a file
while also keeping both the hash and the size the same?

2017-02-28

#webassembly is starting beta

2.28: news.cyb/dev.net/webassembly.org is starting beta:
Mozilla, Microsoft, Google, and Apple have teamed up
to make the web more efficient.