To be clear, I intend for the OP to leave Snow Leopard on the external drive. There is some controversy regarding whether running Snow Leopard in a VirtualBox virtual machine would violate the SLA. This option might require Snow Leopard be version 10.6.8. This should be either Yosemite or El Capitan.
MAC OS X 10.6 SNOW LEOPARD ISO INSTALL
Transferred the file to the 2013 iMac and install the software.Īnother possibility would be to boot to OS X Recovery over the internet and upgrade Snow Leopard to the OS X that was originally installed on your iMac.
To install on my 2013 iMac (which does not have an optical drive), I used one of the following solutions.
This software original was in the form of DVD's. However before attempting to use a virtual machine, have you considered installing the crucial software on the 2015 MacBook Air? Most of the software I used, which worked with Snow Leopard, still works with High Sierra. It might be possible to boot the external drive using a Virtual Box machine running on a 2015 MacBook Air. You should not be able to boot the Snow Leopard stored on external drive using 2015 MacBook Air.