Snow Leopard (OSX 10.6.x) and earlier systems are not compatible with iCloud: Lion 10.7.5 is the minimum requirement, Mountain Lion recommended.
You cannot create an iCloud account on Snow Leopard or earlier. If you have opened an iCloud account on a Lion/Mountain Lion Mac or an iOS5/6 device this will be the situation on Snow Leopard:
- You will be able to access email and calendars on the iCloud website at http://icloud.com provided your browser is reasonably up-to-date.
- You will not be able to sync contacts or bookmarks from a pre-Lion Mac.
- You will be able to enter the server settings for email manually in the Mail application and access your email. A pictorial instruction page on doing this is here (for Snow Leopard, or here for Tiger).
- You will not be able to sync your calendars directly.
- Some people have been able to set up calendar syncing by using the method detailed here - this is an unsupported hack and may not be reliable, and may stop working at some future point. (See below for alternatives.)
- Address Book won't sync: this page has a convoluted hack to make it sync which has been reported as working (and as not working by others). I've not tried it. (See below for an alternative.)
To make proper use of iCloud you will have to upgrade your Mac to Lion or Mavericks, provided it meets the requirements.
The requirements for Lion are:
- Mac computer with an Intel Core 2 Duo, Core i3, Core i5, Core i7, or Xeon processor
- 2GB of memory
- OS X v10.6.6 or later (v10.6.8 recommended)
- 7GB of available space
Lion is available in the Online Apple Store ($19.99). Mountain Lion (10.8.x) is also available there at the same price but there seems little point as the system requirements are the same for Mavericks (10.9.x) - which is free - unless you need to run specific software which will run on Mountain Lion only.
The requirements for Mountain Lion and Mavericks are:
- OS X v10.6.8 or later
- 2GB of memory
- 8GB of available space
and the supported models are:
- iMac (Mid 2007 or newer)
- MacBook (Late 2008 Aluminum, or Early 2009 or newer)
- MacBook Pro (Mid/Late 2007 or newer)
- Xserve (Early 2009)
- MacBook Air (Late 2008 or newer)
- Mac mini (Early 2009 or newer)
- Mac Pro (Early 2008 or newer)
It is available from the Mac App Store (in Applications).
You should be aware that PPC programs (such as AppleWorks) will not run on Lion or above; and some other applications may not be compatible - there is a useful compatibility checklist at http://roaringapps.com/apps:table