Tag Archives: Mac

Avoid losing old Time Machine backups

Every now and then you get a problem with OS X’s Time Machine function. When that happens the system asks you to start a new backup which results in you losing all previous backups.

It hasn’t happened to me for more than two years or so and even if it does usually I have something in place so that I don’t lose my backups: My NAS backs up to another NAS that can take snapshots, so usually I’d be able to rollback to a previous snapshot of the Time Machine.

Unfortunately, when this happened to me recently I had just deleted the previous snapshots because I was running out of space and didn’t want to buy another hard disk – so I couldn’t roll back to a previous snapshot.

Well, for now I have just created a new Time Machine share, meaning that if I need to go back I can access the old Time Machine in the previous share.

PS: When I had an Apple Time Capsule this problem occurred every few months. With y Synology NAS it only seems to happen every few years.


Downloading a merging a .ts stream in OS X

Another brain dump to help me remember if I need to do this again.

Install wget

Install and make wget, information taken and updated from another blog.

curl -O http://ftp.gnu.org/gnu/wget/wget-1.18.tar.gz

tar -xzf wget-1.18.tar.gz

cd wget-1.18

./configure --with-ssl=openssl


sudo make install

cd .. && rm -rf wget*

Download video

Find file location in Safari’s Page Resources, then use with wget

wget -r http://filelocation/filename_{1..999}.ts

Merge files

cat filename_?.ts filename_??.ts filename_???.ts > all.ts



Another command I want to write down, like dot_clean, so that I remember the details:
diff – Compare files line by line.
Usage: diff [OPTION]… FILES
FILES are `FILE1 FILE2′ or `DIR1 DIR2′ or `DIR FILE…’ or `FILE… DIR’.

diff -rq folder1 folder2

e.g. -r (rekursive) and -q (brief output)

diff -rq /Users/memm/Backup/Documents/ /Volumes/Documents/


I keep forgetting this command – I just don’t use it often enough, so I thought I write it down to make it easier to find. I need it when I copy mp3 files to a SD card for the car.

The command to delete hidden system files in OS X is:

dot_clean folder/

Just to spell it out, you can see all files (including hidden ones) using:

ls -a

MacBook Air 2014

After starting life as a place where I write down Raspberry Pi settings or discoveries this blog seems to become a dump for my general computer thoughts, at least at the moment.

The new MacBook Air

A few days ago I ordered a new MacBook Air, the 2014 version. I bought the 2010 version, that was the first one with a SSD, when it was new – and I’ve been very happy with it. The battery info only showed a few charging cycles >100 (rated: 1000), so it seems as if there’s still a lot of life left in this laptop.

What’s better

…but with Apple’s tempting offer, a voucher on top of the education discount, I coulnd’t resist. Other reasons to get the latest version were the specs when compared to the  2010 model:

  • twice the hard disk space (I was always very careful with the space available, so didn’t run into too many problems yet)
  • ~3x as fast (the 2010 version felt a bit slow after the Mavericks update)

On top of that the new version also has

  • twice the RAM
  • ~3x the battery life

…but these last two factors didn’t seem that important to me.


What’s worse

There wasn’t really much time yet, but there are a few things I noticed – where the new version is worse than the old version – at least in my mind. Others might have different priorities and might not mind at all.

  • The keys feel much cheaper. My guess is that this is caused by the different, more plasticy noise they make, not as ‘low’ as the noise from the old keyboard. This might be caused by the fact that the keys are not backlit, which might mean that they’re more ‘hollow’.
  • The new MagSafe power connector is more bulky. The old one could just be used with some particularly chunky USB adapters plugged in next to it. This is not possible with the new connector. It doesn’t matter though for normal USB cables plugged in next to it.
  • The corner of the bottom half seems much less rounded off. This means it’s much less comfortable to rest your hands on the corners of the laptop – in fact it seems quite uncomfortable to me.
  • If you want to use the F5 button you’ve got to use the Fn key now to get to it.

On a positive note: the # key is marked on the keyboard now. Becasue I switch between different language versions and systems of keyboards I tend to forget where some of the special characters are, so I had to mark the key for # with a pen on my old laptop.

Apple Reinstall Drive

The new MacBook Air doesn’t come with a Reinstall Drive any more. It probably makes sense, as most users upgrade to the latest version of OS X anyway. I’m not sure whether the new MacBook Air has a reinstall partition. My old one didn’t, so I reinstalled it from the web, using “Command R”, and despite my fast internet connection (60Mb/s) it took quite a while. The Reinstall Drive looks so good, it’s a shame that as far as I know Apple didn’t sell USB sticks with this design.


German .keylayout file for PC keyboards on a Mac

…and now: a blog post about using a German PC keyboard on a Mac. Unless you speak German this topic is probably not very interesting for you, so I wrote this blog post in German.

.keylayout Datei
Da die Belegung einer Apple Tastatur einige Unterschiede zur üblichen PC 105 Tasten Tastatur aufweist und ich die Belegung der Sonderzeichen nicht auswendig kenne ist die Verwendung einer .keylayout Datei unter OS X sinnvoll.

Als ich mir 2007 einen Mac Mini gekauft habe wollte ich meine geliebte Cherry G80 3000 Tastatur verwenden …und nicht die Apple Tastatur von meinem iMac G3. Die Cherry Tastatur hat den schönen Klick-Druckpunkt – zwar nicht so schön wie der von der IBM XT Tastatur die ich bei der Bundeswehr verwenden durfte (wahrscheinlich Model F), aber doch um einiges besser als der Druckpunkt der Apple Tastatur.

Tasten vertauscht
Zum Glück hatte ich damals die .keylayout Datei bei www.nullpointer.de/stuff/keylayout/index.de gefunden. Leider hat diese Datei jedoch nicht ganz so funktioniert wie sie sollte. Bei meiner Tastatur waren die ^ Taste (neben der 1) und die < Taste (neben dem Y) vertauscht.

Nach kurzer Suche habe ich dann zum Glück Ukelele (http://scripts.sil.org/ukelele) gefunden – ein Editor für .keylayout Dateien mit dem ich eine für mich passende .keylayout Datei erstellen konnte.

Neue Version
Die Cherry Tastatur kam dann irgendwann in mein Büro und für daheim hatte  meine Frau mir eine Apple Tastatur gekauft, weil sie ihre so mag. Da ich inzwischen aber wieder eine deutsche PC Tastatur unter OS X verwende habe ich eine neue .keylayout Datei erstellt.

Da andere Benutzer vielleicht das gleiche Problem wie ich haben:
-> Hier meine .keylayout Datei bei GitHub – für eine übliche 105 Tasten Tastatur.
Einfach die Datei speichern, falls der Webbrowser fragen sollte: nicht als Text Datei sondern als normale Datei speichern.

Zum Installieren (Anleitung wie bei nullpointer.de):

  1. Die .keylayout Datei in das Verzeichnis Library / Keyboard Layouts kopieren.
  2. Neustart bzw. Ab- und Anmelden
  3. In die System Preferences bzw. Systemeinstellungen
    dann in Language & Region bzw. Sprache & Region
    dann Keyboard Preferences… auswählen bzw. Systemeinstellung „Tastatur“…
    über + eine neue Belegung hinzufügen
    die Tastaturbelegung findet sich dann am Ende der Liste unter Others bzw. Andere

install keyboard