Booting OS X Snow Leopard in 32 bit mode

Recently ran into an issue on a MacBook Pro and programming a Logitech Harmony 900 remote with communication when uploading the new configuration. The Program would just prompt to plugin the remote to the USB and would never recognize it was plugged in. After doing a bit of digging in the forums found the issue was with the Mac OS X drivers from Logitech for Harmony Remote 7.7.0 were 32 bit only.

Currently the only solution is to boot OS X into 32 bit mode. While searching through Apple support I found the solution to reboot the system into 32 bit mode which resolved the issue.

You can use either of these methods:
Method 1: Startup key combination (for current startup only)

  •     If your Mac uses the 32-bit kernel by default, but supports the 64-bit kernel, you can start up using the 64-bit kernel by holding the 6 and 4 keys during startup.
  •     If your Mac uses the 64-bit kernel by default, you can start up with the 32-bit kernel by holding the 3 and 2 keys during startup.

Your Mac will revert to the default kernel the next time you reboot it. This is the method I chose as it is just for that session.

Method 2: On-disk setting (persistent)

To select the 64-bit kernel for the current startup disk, use the following command in Terminal:

To select the 32-bit kernel for the current startup disk, use the following command in Terminal:

Note: This setting is stored in the /Library/Preferences/SystemConfiguration/ file and will take effect every time you start up from this disk. If you start up from a different disk, the setting on that disk, or the hardware default, will take effect.
Additional Information

Keys held during startup (such as 3-2 or 6-4, method 1 above) will override the setting in (method 2 above).


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