If the computer has at least 1GB of RAM, it can be upgraded to Mac OS X 10.6.3 and then 10.6.8. MacBook Pros with a Core 2 Duo(not Core Duo) or better CPU can be upgraded further, but going through Mac OS X 10.6.8 is needed to do so.
You don't need to buy a new computer, as any MacBook Pro model released in the last 5 years with sufficient RAM can run 10.8.3.
OS X Mountain Lion system requirements
To install Mountain Lion, you need one of these Macs:
- iMac (Mid 2007 or newer)
- MacBook (Late 2008 Aluminum, or Early 2009 or newer)
- MacBook Pro (Mid/Late 2007 or newer)
- MacBook Air (Late 2008 or newer)
- Mac mini (Early 2009 or newer)
- Mac Pro (Early 2008 or newer)
- Xserve (Early 2009)
Your Mac needs:
- OS X v10.6.8 or OS X Lion already installed
- 2 GB or more of memory
- 8 GB or more of available space
If your macbook pro doesn't meet the above requirements - see the requirements for Lion.
OS X Lion system requirements
To use Lion, make sure your computer has the following: