A good old trusty Mac Pro needed repaving (about my Mac says it is a Mac Pro (early 2009) with 2.66 GHz Quad-Core Intel Xeon, NVIDIA GeForce GT 120 512 MB, 8 GB 1066 MHz DDR3 ECC).
I decided to replace the book disk with a 1TB Samsung SSD (850PRO) before reinstalling OS X and Windows 10. Swapping out the disk labeled (1) and installing the 2.5” SSD in an ICY DOCK EZConvert case (ref. MB882SP-1S-2B) was easy.
Reinstalling macOS
I expected the reinstall to be painless. I turned the Mac Pro on
while holding down Option-Command-R to trigger the web-based recovery
process. All I got was a black screen with the No bootable device --
insert boot disk and press any key message.
To get over that, I needed to reset the PRAM where the incorrect boot configuration was stored. For that, I pressed Option-Command-R-P while turning on the Mac Pro. It then rebooted and showed a folder icon with a question mark. Obviously, it was now trying to boot from the empty SSD and not finding the recovery console.
The Mac Pro appears to be too old to support web-based recovery, so the next step was to install macOS Sierra on the SSD from the outside.
Target mode reinstall
I happen to have a Mac laptop on which I downloaded the macOS Sierra installer, so I decided to give it a try.
I pressed T on the Mac Pro while turning it on in order to start it
in target mode. Then, I connected the Mac Pro to the laptop using a
FireWire cable (attached to a lightning connector over an adapter).
The SSD appeared on the laptop. I could initialize it and mount it.
Then I selected that disk as the target in the Sierra installer.
A few minutes later, the installer had finished its job and was ready to reboot the laptop. Instead, I decided to unplug the Mac Pro and reboot it. That was, alas, a dead end: the installer booted, but only to tell me that my Mac Pro was not supported by this macOS installer. Great.
Old fashioned DVD reinstall
I had fortunately a Mac OS X DVD Install DVD in my archives (2007) and I decided to give it a try. Rebooting the Mac Pro while holding down Alt, I could then open the DVD tray (use a real Apple keyboard), insert the DVD and boot from it. Alas, my Mac OS X v10.5 DVD would only boot up to the Apple logo, and get stuck there.
I suspected that the newer file system on my SSD drive was somehow confusing the 10.5 installer. I wiped the SSD (using once more the target mode) and rebooted.
The installer finished to load, only to inform me that my Mac model was not supported.
I then digged into my stack of installation DVDs and found one which was bundled with a Mac mini (version 10.6.4). It booted, but refused to install, since the hardware did not match. Sigh.
Back to target mode reinstall (this time with success)
I decided to try an older version of OS X (as Sierra is documented to no longer support old Mac Pro models), so I picked Mac OS X El Capitan which I downloaded through the App Store on my laptop.
Back to target mode. I once again installed the OS on the Mac Pro over FireWire, running the installer on my laptop. But this time, I let the laptop reboot and finish the install, then turned it off.
I restarted the Mac Pro and – lo and behold – it happily booted to the desktop. Mission accomplished. I then checked to see if the installation did somehow affect the laptop. Thankfully, all changes were done on the Mac Pro SSD and the laptop disk was left unmodified.
Installing Boot Camp
I used the Boot Camp Assistant to download the additional drivers needed by Windows (they get saved to an external USB key) and a physical DVD containing Windows 10. The install went smoothly and without surprises, even if the drivers are designed for Windows 7.