Category Archives: Computers

Mac OS X and Windows

Apple MacOS UK Keyboard Layout for Windows & the Command key for Control

If like me, you swap between Mac and PC you’ll have been irritated by everso slightly different keyboard layouts. So here’s my Apple Extended UK Keyboard Layout for Windows Installer.

When I wrote it I was using one of these:
Apple Pro Keyboard
But since the Apple full-size layout hasn’t actually changed since then, I still use it for my aluminium keyboard.

Swapping between Mac and Windows

In addition – even if using a PC keyboard – a Mac-PC swapper will undoubtedly suffer repeated Cmd and Ctrl shortcut confusion: You want to type Cmd-X for cut and suddenly the Win-X menu comes up instead.

My preferred solution for this is an AutoHotkey script, partly because after using Autohotkey for a few weeks I realised it was an utterly brilliant, all-singing, all-dancing customise-your-Windows-in-every-way tool, with an all-but-zero footprint.
My script is, which also has shortcut keys for arranging windows on a big screen.

The other reason I use autohotkey is that it enables a cherry-picking approach to swapping or duplicating Cmd-key/Ctrl-key shortcuts, which I find works much much better than doing a straight Cmd<=>Ctrl key swap. I got this approach from the keyboard layout used by Parallels on the Mac, which simply duplicated common shortcuts such as Ctrl-X, Ctrl-V to the Cmd-key. If you swap regularly between Mac & PC, this approach works well.

Inverting Mouse Scroll Direction

Since about the time that iPhone launched, OS X scroll direction, both mouse and keyboard, has used the metaphor of “push the document up to move it up the window” rather than the previous “push the scroll bar up to move the document down the window.” Windows has stayed firmly on the scrollbar metaphor.
Oddly enough, Microsoft mice come with a Windows driver that let you reverse scroll direction via the UI. For other mice, you can FlipFlopScrollWheel. Oddly, this is not per-user but per mouse/usb port combination, which means if you plug the same mouse into a different port it’s scrolls in the opposite direction.

Back to the Keyboard

If you do want a more complete Cmd<=>Ctrl key swap, then you do it with Randy’s SharpKeys.

Warning! You can’t swap keys around with it so do just this: map Left-Windows key to Left-Control. The right windows key will then still open the Windows menu and do all the Windows-Key stuff that it should do, such as Windows-L for Lock screen/Switch User:

Sharp Keys: Map just the left Windows key to Control key

If you want other keyboards than Apple UK, download the Microsoft Keyboard Layout Creator to tweak your layout.

WordPress – Unable to create directory – Is its parent directory writable by the server?

One of the annoyances of teh interwebs (mostly stackexchange, actually, but not in this case) is when the wrong answer comes top of the google rankings for a common question.

So here’s my contribution to making WordPress Forums for Unable to create directory – Is its parent directory writable by the server? the top google hit for this problem.

The problem, for me and many others, is not directory permissions but the path-to-uploads setting. Fix it by logging in with your admin account, and correct the path in:

Settings -> Media -> Uploading Files : Store uploads in this folder

WordPress Settings Media Upload Path

Why was it incorrect in the first place? Because I had changed hosting provider.

Use a Windows NTFS, or Linux, or other–formatted disk for Apple Time Machine Backups

It is well known that you have to use an Apple formatted disk (HFS+) for Time Machine Backups and you can’t use an NTFS formatted disk, or any of the preferred *nix disk formats with Time Machine.

Except you can.

Gotchas And Caveats

It’s not always a first choice option:

  • If your Windows drive is connected over USB2, it will be much slower than a Mac disk connected over Thunderbolt or FireWire. My first backup of 120GB took about 10 hours, aka all night. But that was still better than no backup whilst waiting for a new drive to arrive in the post.
  • The backup volume will not auto-mount when you plug the drive in. You must manually double-click the <YourMachineName>.sparsebundle in the Finder each time you plug the drive in. After that, Time Machine backups will run as normal.


  • Plug in your foreign-formatted disk and get a read/write driver for it
  • Save the the script from tmMakeImage script in, for instance, your Downloads directory.
  • Open a terminal window.
  • If you saved to Downloads, then something like this should make the script executable and show you command line usage:
    cd ~/Downloads
    chmod a+x tmMakeImage
    mv tmMakeImage /usr/local/bin
  • So if your external drive has a Volume called WinDrive, and your Mac drive is about 250GB then this command should initialise it for Time Machine backups:
    tmMakeImage 500GB /Volumes/WinDrive GO
  • Optionally, follow up with an immediate tmutil startbackup

Opening the Time Machine preferences should now show that you have “Time Machine Backups” selected as your backup drive. Don’t forget to double-click the sparsebundle each time you attach the drive, to mount your Backup Volume and allow Time Machine to do its stuff.


Using Sparsebundles to create HFS+ formatted drive on a ‘foreign’ disk format

Apple created, it seems, sparse images and sparse bundles to solve the problem of saving backups on a network drive. Time Machine uses and recognises them. It will even auto-mount the sparsebundle disk image when you re-attach the drive in order to start running a backup.

Local drives and network drives

Most instructions on the web focus on network drives. Good instructions without any command-line stuff is here: For network drives, the sparsebundle name includes your Mac’s MAC address which it doesn’t need to for a locally-connected drive.

Things Under the Hood of Time Machine Disks

  • You can’t create a sparsebundle directly on a network or ‘foreign’ drive so the typical thing is to create it on your machine first, and then copy it to its final destination.
  • Sparsebundles don’t use up empty space. An sparsebundle declared as 500GB but still empty will only take up a few megabytes of real disk space.
  • A sparsebundle used by Time Machine has a file in the package, which contains the UUID of the physical machine it belongs to. This stops you accidentally using backups on the ‘wrong’ machine. (Time Machine does let you browse and use ‘wrong’ backups though).
  • A Time Machine drive must have “Ignore ownership permissions” Off, whereas by default the Mac mounts external drives with “Ignore ownership permissions” set to On. This setting is not stored on the drive itself; it’s stored on your machine and can be specified each time the drive is mounted (man hdiutil) or specified permanently (man vsdbutil)
  • You can set the Time Machine destination to a sparsebundle on an attached drive by first mounting it then doing tmutil setdestination /Volumes/Volumenameonceitsbeenmounted. You mount the image either by double-clicking it in Finder, or with hdiutil attach /path/to/image.
  • Learn More:
    man tmutil
    man hdiutil
    man vsdbutil
  • You can still use your backup disks for other files alongside your Time Machine backups. Just don’t touch the Backups.backupdb folder! The Finder will protect it to some extent; it doesn’t let you modify things in there, but it will let you delete and add things.
  • The Script

    Most of the things in the tmMakeImage script can be found on the net going back to 2007, but you’ll still find recent answers on the internet saying it can’t be done.

Mac OS X Command Line: Start a process and pick it up later

I can’t believe I’ve only just discovered the gnu screen command. You want to kick off a long running command line process and come back to it later? Like so:

  • Open a Terminal window
  • Type screen
  • Type ls -R /
  • Quit Terminal, and hum to yourself for a few seconds
  • Open a new Terminal window and type screen -R

Now that’s what I call magic.

It survives logouts and is of course an essential for working with remote or cloud machines over ssh; when your network connection fails you can log back in and carry on. man screen will tell you more, although so will