Boot from External HD

If you are looking fo a newer mac and you want it to be able to run Mac OS X Mavericks 10.9.5

you must make sure the mac did not come pre installed with an OS newer than Mavericks.

Any macs that came preinstalled with Mac OS X Yosemite, Mac OS X El Capitan, macOS Sierra,

macOS High Sierra, macOS Mojave and macOS Catalina will not be able to run Mavericks.

Mavericks was launched in approx September 2013 and was replaced by Mac OS X Yosemite in

approx September 2014. So you are really looking at macs that are made between approx 2007

and mid 2014. As you already have a 2009, then you would be looking at 2010-mid 2014.

Do your research.

Depends on your mac.

If you give some information as to what mac and its year would give people

an idea of which mac OS's it can run.

It is all down to its motherboard/ logic board and its other hardware which OS

it can run, so knowing more about your mac would help.