Need a workaround for installing older Mac Operating systems
文本:
Many times I need to install an operating system other than the current one a machine is running from. I hook up a drive externally with an adapter, go to install but my machine tells me I can't do it because the operating system is newer. I can't get to the drive to select it. i.e. The MacPro is running 10.11.2 but I need to install 10.9 on an external drive to go into say a MacBook Pro 2009. Is there a workaround?