Yet Another Technology Blog

Poetic Unix pipes

Rafael Aroca — Mon, 23 Jan 2012 13:03:27 +0000

http://www.linusakesson.net/programming/pipelogic/index.php

First ARM-based supercomputer

Rafael Aroca — Sat, 14 Jan 2012 00:29:37 +0000

http://pressroom.nvidia.com/easyir/customrel.do?easyirid=A0D622CE9F579F09&version=live&prid=821220&releasejsp=release_157&xhtml=true

http://blogs.nvidia.com/2011/11/world%E2%80%99s-first-arm-based-supercomputer-to-launch-in-barcelona/

Congratulations guys.

A Carma I want to have

Rafael Aroca — Sat, 14 Jan 2012 00:20:37 +0000

Amazing:

Quad Core ARM + GPU with 96 cores = 270 GFlops (theretically)

By the way, some Xeon machines can do 50GFlops, theoretically also

http://www.nvidia.com/object/carma-devkit.html

Small teams are dramatically more efficient than large teams

Rafael Aroca — Thu, 12 Jan 2012 20:18:35 +0000

http://spin.atomicobject.com/2012/01/11/small-teams-are-dramatically-more-efficient-than-large-teams/

ARM PandaBoard in a HDMI plug

Rafael Aroca — Mon, 09 Jan 2012 00:22:39 +0000

http://www.alwaysinnovating.com/products/hdmidongle.htm

Computers in Spaceflight: The NASA Experience

Rafael Aroca — Sun, 08 Jan 2012 02:35:04 +0000

Amazingly good and entertaining reading:

http://history.nasa.gov/computers/contents.html
http://history.nasa.gov/computers/Ch6-2.html

Open in terminal

Rafael Aroca — Sat, 07 Jan 2012 13:06:31 +0000

sudo aptitude install nautilus-open-terminal
nautilus -q

Then, in any folder you are, simply click “Open in terminal” and will get a terminal at that directory.

Swapping keyboard’s keys

Rafael Aroca — Thu, 05 Jan 2012 01:33:23 +0000

For the second time, an ASUS EEE PC laptop I have started showing keyboard problems. For the first time I replaced the keyboard, with a feeling that the solution would not last long. Well, the problem is back. Some keys (4, w, : and [) stopped working. Certainly they are in the same keyboard scan line/row. I measured the keyboard flat signals and they are fine, so the worst happened: either its a connector problem, solder or a keyboard controller problem.

So, let’s go for the quick and dirty solution (at least works):

The idea is to remap these broken keys to other less used keys. My solution was:

w -> F3
4 -> F4
: -> F5
[ -> F6

I found most answers and solutions to this at
http://madduck.net/docs/extending-xkb/, which is, by the way, a great tutorial on this subject.

1. Using another computer, we can check which keycodes are generated by each of these keys using:
$xev | sed -ne ‘/^KeyPress/,/^$/p’

2. Another interesting information shows a graphical keyboard and the corresponding codes:
$xkbprint -label name $DISPLAY > keyboard.ps
$gv -orientation=seascape keyboard.ps

3. The solution works seamlessly in 3 steps

Step 1: Dump the keyboard map to a file
xkbcomp :0.0 teste.dump

Step 2: Edit the keyboard map
vim teste.dump

Then replace,

= 70;

= 13;

this will replace the function of the key to the function key 4 (F4). Then repeat the same steps for the other keys (look at keyboard.ps to check the corresponding keycodes)

Step 3: Load the new keyboard map
xkbcomp teste.dump :0.0

Final step, add this to .xprofile to make it permanent

More ARM curiosities

Rafael Aroca — Wed, 21 Dec 2011 18:18:20 +0000

http://www.engadget.com/2011/12/20/the-engadget-interview-arm-co-founder-john-biggs/ http://elleeseymour.com/2011/05/24/how-the-arm-chip-saved-apple/

Christmas Toy: Gumstix

Rafael Aroca — Sun, 18 Dec 2011 02:28:33 +0000

Today I received a Gumstix FireSTORM and some accessories I ordered for my PhD project. For people in Brazil, the price was U$ 500,00 (about R$ 1.000,00) and the taxes were also R$ 1.000,00 (!!). Yes, the import taxes were the same price as the products, doubling their price.

The gadgets came very well packaged in organized and separated boxes. I simply mounted FireSTORM in the top of Tobi, powered Tobi with a 5V power supply, and got Angstrom-Linux running in less than 5 minutes after opening the box with ethernet, wifi, bluetooth, ssh, etc. Also, the USB console was very useful in the first boot so that I could setup the network interfaces.

Some photos:

https://picasaweb.google.com/113280981037754135094/Gumstix