On Sunday, January 22, 2017 2:08:59 PM CET Michael Fothergill wrote: > you need to play with the bios on your Mac box to get it to boot from the > debian DVD.
The point is that, in contrast to all other PCs I had, on Macs you cannot enter the BIOS setup and configure the boot order. You have to press the "Option ⌥" key while powering on the Mac. That will allow you to enter the Startup Manager, where you'll see a list of all bootable devices available, and choose the one you need (e.g. a bootable DVD-ROM).
