Some Cellular Device Terminology

Cellular devices have many numbers associated with them, especially with respect to the SIM cards. Here’s a short list to keep them straight:

IMEI stands for International Mobile Station Equipment Identity and is used to identify 3GPP (also known as GSM (AT&T, TMobile, UMTS and LTE devices/networks) and iDEN mobile phones, as well as some satellite phones. It is usually found printed inside the battery compartment of the phone and often on the box the phone came in (think iPhone), but can also be displayed on-screen on most phones by entering *#06# on the dial pad, or alongside other system information in the settings menu on smartphone operating systems.

The IMEI is part of the phone, not the SIM card so swapping SIM cards won’t change the IMEI. (Kind of like a serial number)

ICCID stands for Integrated Circuit Card ID. This is the identifier of the actual SIM card itself – i.e. an identifier for the SIM chip. It is possible to change the information contained on a SIM (including the IMSI), but the identify of the SIM itself remains the same.

This allows you to swap SIM cards between phones and makes GSM style phones more convenient to use when you break your phone and want to swap it with a spare.

SIM stands for subscriber identification module and is basically the serial number of the card that you put in your GSM phone.

SIM cards come in many sizes, currently they are:

SIM card Introduced Standard reference Length (mm) Width (mm) Thickness (mm) Volume (mm3)
Full-size (1FF) 1991 ISO/IEC 7810:2003, ID-1 85.60 53.98 0.76 3511.72
Mini-SIM (2FF) 1996 ISO/IEC 7810:2003, ID-000 25.00 15.00 0.76 285.00
Micro-SIM (3FF) 2003 ETSI TS 102 221 V9.0.0, Mini-UICC 15.00 12.00 0.76 136.80
Nano-SIM (4FF) early 2012 ETSI TS 102 221 V11.0.0 12.30 8.80 0.67 72.52
Embedded-SIM JEDEC Design Guide 4.8, SON-8 6.00 5.00 <1.0

UICC is the physical card most users refer to as a SIM. It stands for Universal Integrated Circuit Card. The SIM is a circuit component of this card.

Hope that helps. It’s shocking how the carrier customer service reps have no idea what any of this is an always ask you to read the longest number possible when they know full well the don’t need it….

How To Add TRIM Support on your Mac SSD

It is possible to do this by hand using the Terminal. It looks ugly but essentially what you’re doing is patching a low-level system file to allow TRIM to function with your SSD.

Just to be on the safe side, back up the file we’re modifying. Copy the following into a new Terminal window and hit Return (the Enter key).

sudo cp /System/Library/Extensions/IOAHCIFamily.kext/Contents/PlugIns/IOAHCIBlockStorage.kext/Contents/MacOS/IOAHCIBlockStorage /System/Library/Extensions/IOAHCIFamily.kext/Contents/PlugIns/IOAHCIBlockStorage.kext/Contents/MacOS/IOAHCIBlockStorage.original

You’ll be prompted to enter your administrative password, so type it in and press Return once more.

Use the following command to modify the kernel extension so that it activates TRIM support.

sudo perl -pi -e 's|(\x52\x6F\x74\x61\x74\x69\x6F\x6E\x61\x6C\x00{1,20})[^\x00]{9}(\x00{1,20}\x54)|$1\x00\x00\x00\x00\x00\x00\x00\x00\x00$2|sg' /System/Library/Extensions/IOAHCIFamily.kext/Contents/PlugIns/IOAHCIBlockStorage.kext/Contents/MacOS/IOAHCIBlockStorage
Important: This code is intended for use on OS X Mountain Lion 10.8.5 or above or OS X Mavericks.

To make the changes take effect, you need to manually refresh the kernel extension cache.

sudo touch /System/Library/Extensions/

Once done, reboot and TRIM should be active.

Fixing Mac OS X Permissions from Terminal

I support a lot of Macs and it’s much easier to work on them remotely via SSH to do things like permission fixes, ACL repairs and other sneaky things. Here’s how to repair permissions from SSH/Terminal:

diskutil repairPermissions /

Of course you may need to sudo or use the su command to do this.

You can also do a repair disk this way too but that may dismount the users active drive so use with caution:

diskutil repairdisk /

 

Mac OS X Screen Shot Commands

I started like with a Mac Classic running System 5, then slowly moved to newer Macs running System 6, 7 , 8 and 9. Then I started working mostly on Windows. I take it for granted that Windows has a single key for screenshots and now an app to do partials.
Naturally I now support lots of Macs and I finally need to learn the Mac versions. So here they are:

Command-Shift-3

This captures a screenshot of your entire screen/screens.

Command-Shift-4

This turns the cursor into a crosshair, which you can drag to select a portion of your screen to capture. Release the mouse button or trackpad to take the shot.

Command-Shift-4, then space bar, then click on a window

Hitting the space bar turns the crosshair into a little camera icon, which you can move over any open window. Click on your desired window to take a screenshot of it. A screenshot captured by this method features a white border around the window with a bit of a drop shadow.

All screenshots are dropped on the desktop as an image file.

And if you happen to be using Log Me In to make the screenshots on the remote computer the screen shots won’t appear on the remote desktop…they show up on your local desktop….