You have to understand the difference between an Update and an Upgrade.
An Update is a free change to add to the base code or as a bug fix within an existing Operating System. Such as the .8 added to 10.5.
An Upgrade is a complete new Operating System that must be purchased. Such as 10.5 Leopard to 10.6 Snow Leopard.
10.5 Leopard was based on Power PC code and was written to be able to run on both Power PC and Intel processors.
10.6 Snow Leopard has completely rewritten code and only runs on Intel Macs.
10.7 Lion used some 32 bit which allows it to run on Late 2006 through Early 2008 MacBooks and a lot of 64 bit code.
10.8 Mountain Lion is pure 64 bit, which excludes more systems than Lion did. It can only run on the Late 2008 through Mid 2010 MacBooks. It's not something you can add memory to, for example, as it involves the base architecture.
The 10.6 Snow Leopard DVD is back in the Apple online store. You can now get it for $19.99 without having to phone the store. http://store.apple.com/us/product/MC573/mac-os-x-106-snow-leopard
The Early 2006 model 1,1 Core Duo can only run a maximum of 10.6 Snow Leopard.
The models Late 2006 Core 2 Duos 2,1 through Early 2008 4,1 can only run a maximum of 10.7 Lion.
The Late 2008 model 5,1 Aluminum Unibody through the Mid 2010 White Unibody model 7,1 can run 10.8 Mountain Lion.
To see which model you have go to the Apple in the upper left corner and select About This Mac, then click on More Info. When System Profiler comes up check the Model Identifier and post it back here.
Once you are at 10.6.8 Lion is still available from Apple. You will have to call Apple Customer Care 1-800-692-7753 or 1-800-676-2775. to purchase it. Then within 3 days you will get an email with a code which you can use to download Lion from the App Store. The price is $19.99.
You must have at least a model 2,1 MacBook. Lion will require at least 2gb of RAM but really needs 4gb to run smoothly.
As for third party programs see this list for compatibility with 10.7 http://roaringapps.com/apps:table
Also Lion doesn't run any Power PC programs. To see if you have any Power PC programs go to the Apple in the upper left corner and select About This Mac, then click on More Info. When System Profiler comes up select Applications under Software. Then look under Kind to see if any of your applications are listed as Power PC. Universal and Intel will run under Lion.
Before Mac switched to Intel processors in 2006 they used Power PC processors from 1994 to 2005. Power PC 601 through 604, G3, G4 and G5. Applications written for the Power PC processors need the application called Rosetta to run on Intel processors. This was part of the Operating System in 10.4 and 10.5 but was an optional install in 10.6. With 10.7 Lion Apple dropped all support for Power PC applications
Thanks for the info. The following is the hardware overview from my MacBook:
Model Name: MacBook
Model Identifier: MacBook5,1
Processor Name: Intel Core 2 Duo
Processor Speed: 2 GHz
Number Of Processors: 1
Total Number Of Cores: 2
L2 Cache: 3 MB
Memory: 2 GB
Bus Speed: 1.07 GHz
Boot ROM Version: MB51.007D.B03
SMC Version (system): 1.32f8
Serial Number (system): W88****1B0
Sudden Motion Sensor:
All but a few applications are either intel or universal. The 4 or 5 that are Power PC are not needed anymore. They were installed and used when I was teaching, and I'm retired now.
1. How do I find out if I have enough ram to run Lion?
2. If I install Lion, will I lose any documents or files?
3. Can I switch directly to Mountain Lion or do I have to upgrade to other versions first?
4. Is there a large learning curve to switching to Mountain Lion? I had some problems when I switched from my old Mac laptop to the MacBook, because the operating system was so different. I also could not transfer any of my original documents and files from my old Mac to my new MacBook, therefore I lost all of them, even though I had gone to the trouble of saving them on a memory stick, because I could not access them. That was very dissappointing, and I don't want to go through that again. Sadly, no one at Apple told me about that when I ordered my MacBook.
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The model 5,1 http://www.everymac.com/systems/apple/macbook/specs/macbook-core-2-duo-2.0-alumi num-13-late-2008-unibody-specs.html can use up to 8gb of RAM (Random Access Memory). Thats the Memory in the overview. These are good online stores for Mac compatible RAM.
OWC http://eshop.macsales.com/shop/memory/Apple_MacBook_MacBook_Pro/Upgrade/DDR3 - They offer Mac tested RAM at very good prices.
Data Memory Systems http://www.datamemorysystems.com/apple-memory.asp - another good, cheap place to buying RAM if you live in the U.S.
Here are video instructions on replacing the RAM on the Aluminum Unibody.
If you don’t have the tools to open up the MacBook OWC has a set for $5.
You would have to upgrade to 10.6 and then update it to 10.6.6 to use the full 8gb of RAM and to get the App Store which you can use to upgrade to 10.8 Mountain Lion. You can go straight from 10.6 to 10.8 without installing 10.7 Lion.
I can't really advise you on Mountain Lion since I'm still running Snow Leopard. You might try posting in the Mountain Lion forum https://discussions.apple.com/community/mac_os/os_x_mountain_lion