Can I store old operating system while using current one?

Question

I am currently running MountainLion 10.8.3 and need to use Snow Leopard 10.6 for use with an old GPS device that needs this system to download maps. Can I download and keep SnowLeopard for use with some older devices then run Mountain Lion?

Answer 1

lenmarstelly wrote:
Can I download and keep SnowLeopard for use with some older devices then run Mountain Lion?
The safest way is to run Snow Leopard in a virtual machine under 10.8, this works enough for what your needing without being hardware demanding also it works on Mac's that never had 10.6 at all, like the ones with 10.7 and 10.8
Unfortuntly it's a hack, you can find out how to go about it on the MacRumors forums.
If your machine had Snow Leopard at one time and you don't have BootCamp, then you can use Disk Utility or the BootCamp software to create a second partition on your boot drive. If you use Bootcamp software to create the partition, you have to change the partition in Disk Utiltiy to "Snow Leopard" and give it a OS X Extended Journaled format.
Once the partition is created, then you can hold c or option/alt on a wired or built in keyboard to boot from the 10.6 machine disks (or if your Mac originally came from the factory with pre-10.6.2 can use the white 10.6 retail disks) and install Snow Leopard into the Snow Leopard partition only.
Holding option/alt key at boot will then allow you to boot directly into either 10.8 or 10.6
You can also install Snow Leopard on a external powered drive, it has to first be formatted Partition 1, Option: GUID and Format OS X Ext J first in Disk Utility, then repeat the same 10.6 install procedure.
The advantage of it being on a external drive is it's less risky than messing with your internal drive, but it's slower a bit than being on the faster internal connections.
Read through my many User Tips here and you'll be up to speed
https://discussions.apple.com/community/notebooks/macbook_pro?view=documents#/?p er_page=50