Raspberry Pi, Raspbian and an old TV with DVI

rpi_8

I finally bought some Raspberry Pi stuff. I picked up the package yesterday after my night shift at and mounted one of them in the case I got for it and connected it to my ancient tv, with DVI as the most modern input choice.
The first thing I tried was raspbmc. It boots, and works, bMy Raspberry Pi in its Pi Holder aluminum case, and some dust.ut I’m not very impressed with XBMC, and not with the analog audio, which doesn’t work at all in it, except for a few seconds when listening to a radio stream, but most of the time it was only giving some clicks in the speakers when switching streams. It’s not for me anyway. Moving on.

Then I fell asleep, and now it is Saturday.

 

Raspbian

So, off with that. Next thing to try will be the Raspberry Pi foundation Raspbian image. (After that I will probably end up using the Raspbian installer and make my own stripped down base image, or check if there exists some sane image from here, we’ll see.). Continue reading “Raspberry Pi, Raspbian and an old TV with DVI”

TPB AFK

TPB AFK: The Pirate Bay Away From Keyboard är en dokumentär om The Pirate Bay och dess grundare som hade premiär igår på Berlins filmfestival och online. Filmen har tagit fyra år att färdigställa och följer de tre grundarna av The Pirate Bay under rättegångarna. Filmen sägs vara den första film som har premiär både online och på en större filmfestival samtidigt, den kan ses och delas fritt.

På YouTube har den hitintills setts av cirka 103000 personer i skrivande stund.

Här finns fler länkar till filmen i olika format.

Earth Hour 2012

Today is Earth Hour 2012.
Most lights in the office are shut off. I’m working the night, I usually do that whenever I work alone, but doing it with a thought today.

Changing the theme to require less energy to display (in theory, on CRT:s anyway 🙂 ).

Securing the MikroTik RouterBOARD RB751G-2HnD (or any RouterOS device) – the bare minimum

Before you do anything else with the MikroTik RouterBOARD RB751G-2HnD, or any other device running RouterOS with a default configuration I guess, you should configure the device with some bare minumum security features.

Set a password

The first thing to do is changing the password for the default user “admin”. When you are logged in, you can do this two ways (at least), either by setting it directly:

[admin@MikroTik] > user set admin password=somegoodpassword

Or by using the “password” utility to set the password interactively:

[admin@MikroTik] > password
old password: ********
new password: ********
retype new password: ********

Continue reading “Securing the MikroTik RouterBOARD RB751G-2HnD (or any RouterOS device) – the bare minimum”

Examining, configuring and playing with the MikroTik RouterBOARD RB751G-2HnD for the first time

RouterBOARD RB751G-2HnDI bought a MikroTik RouterBOARD RB751G-2HnD a little while back. Tonight is the first time I power it up and connect to it, examining what it can do, and how to do it. From the outside it’s a nice looking little box, with a seemingly sturdy enough plastic casing with the size of 113x138x29mm. There are holes for passive cooling, some status LEDs, 5 RJ45 ports, and a USB 2.0 port. On the other side there is an antenna connector for an external MMCX antenna.

The labeling on my case is “RouterBOARD 751G”.
Continue reading “Examining, configuring and playing with the MikroTik RouterBOARD RB751G-2HnD for the first time”

If a PDP-8 minicomputer can’t help with Greece, who can?


.BASIC
NEW OR OLD--OLD
FILE NAME--HELLO.BA

READY
RUN

HELLO BA 5A

HELLO, MY NAME IS PETEY P. EIGHT.

WHAT’S YOUR NAME ?BEARDY

HI THERE BEARDY. ARE YOU ENJOYING YOURSELF HERE
IN THIS WONDERFUL PLACE?YES

OH, I’M GLAD TO HEAR THAT BEARDY

SAY, BEARDY, I CAN SOLVE ALL KINDS OF PROBLEMS
EXCEPT THOSE DEALING WITH GREECE. WHAT KIND OF
PROBLEMS DO YOU HAVE (ANSWER SEX, HEALTH, MONEY,
OR JOB)?

Not even a DEC PDP-8 (simulated in SIMH) running OS/8 and a BASIC program, HELLO.BA, can help with Greece!

PDP-8

Guess if I dropped my jaw in surprise and amusement when I read that, when playing around with a simulated historic computer just now. If not even that can help to solve the problems of/with Greece, I guess they’re doomed! 🙂

On another note, SIMH is a great thing, the DEC PDP-8 minicomputer (from 1965) seems to have been a nice machine in its days, and OS/8 quite a decent OS for its time and environment. Expect another post on SIMH and simulating/emulating old computers shortly.

Cron, crontab example reference and how to run things periodically in GNU/Linux and Unix

Cron is a job scheduler found in most Unix-like operating systems. “Chronos”, which is the Greek word for “time”, is where the name cron comes from. Cron makes it possible to schedule jobs, which can be commands, a series of commands, or scripts, that you want to run periodically. Common uses are backups, notifications, periodic checks on availability of services, networks, machines, or other things, and administration and maintenance tasks like rotating of logs, to mention a few. It is very general-purpose though, (like Unix tools is and should be) and can be used for whatever you can think of that needs to run periodically.
Image showing the Big Ben clock.

Jobs that should be run by cron are specified in crontab (cron table) files. A crontab is a configuration file that specifies commands (shell commands, including programs, scripts, or pipelines thereof) to be run, and when they should be executed.

Each line in a crontab file represents a “job”, and is composed of a CRON expression (specifying the time) followed by the command or commands to be executed. There are two different crontab files, the ones installed by system software, and editable only by root (but in most cases best left alone), and crontab files written by and belonging to users (including root). The authorization control to cron, who will be allowed to have a crontab or not, are done with the files /etc/cron.allow and /etc/cron.deny.

The manpages of cron and the crontab format are nice. “crontab” is both the name of the program installing, listing and editing user’s crontabs, and the file format manpage, so do read them:

man cron
man 1 crontab
man 5 crontab

The page in section 5, about the format is most interesting. However I prefer to keep a short reference in my user’s crontab file itself for quick reference, feel free to grab it:

# mycrontab.txt
# beardy
# My example crontab, kept in ~/

SHELL=/bin/sh
PATH=/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin

# Send the mail to another address than the local user
##MAILTO=foo@foo.bar

##############################################################################
#
# The following example should run "true" every day of every month, at half
# past eight, every day of the week.
#
# Example:
#
# 30 8  * * *   true
# |  |  | | |    |
# |  |  | | |    +--- command, or script, to run
# |  |  | | +-------- day of week, 0-7 or mon, Tue, FRI
# |  |  | +---------- month, 1-12, or names, jan, Mar, AUG (case doesn't matter)
# |  |  +------------ date, 1-31
# |  +--------------- hour, 0-23
# +------------------ minute, 0-59
#
# see "man 5 crontab"
#
#     Instead of the first five fields, one of eight special strings may
#     appear:
#
#           string          meaning
#           ------          -------
#           @reboot         Run once, at startup.
#           @yearly         Run once a year, "0 0 1 1 *".
#           @annually       (same as @yearly)
#           @monthly        Run once a month, "0 0 1 * *".
#           @weekly         Run once a week, "0 0 * * 0".
#           @daily          Run once a day, "0 0 * * *".
#           @midnight       (same as @daily)
#           @hourly         Run once an hour, "0 * * * *".
#
##############################################################################

# Run beep every Christmas Eve, at 14:40 (20 min before Kalle Anka)
#40 14  24 12 * beep -f 1000 -r 5 -l 150 -D 250
# next job goes after this line
40 14   24 12 * echo "God Jul!"

To install a new crontab, the crontab(1) program is used:

crontab mycrontab.txt

To later list it, and edit it (with the editor configured with the $EDITOR environment variable usually):

crontab -l
crontab -e

Read more about cron and crontab:

cron(8)
crontab(1)
crontab(5)
Time – An important Subject with any OS

Fixing missing menu entries of Opera and Skype in Debian GNU/Linux

Unfortunately the third-party packages of Opera and Skype do not contain menu entries for the Debian menu system. Not very surprisingly one might think, but I just think it’s sloppy. If you, like me, like the Debian menu system and want Opera and Skype available in it, do the following to solve that, until the packagers have included the menu entry files themselves:

(Update: I noticed that Opera has apparently had a menu entry in its package before, but has now removed it. It’s explained in this post, but I still think that was a bad choice.)
Continue reading “Fixing missing menu entries of Opera and Skype in Debian GNU/Linux”