Startup Disk
I’m not sure how to pose this question but I hope it’s understood.
I have a mid 2010 Mac Pro with 3 drives (one is SSD with High Sierra) other has El Capitan, other is backup.
I booted from High Sierra into El Capitan and now I can’t use startup disk in system preferences to go back because High Sierra on SSD isn’t recognized.
so how do I get back to disk named High Sierra SS ? Thanks in advance!
Mac Pro, macOS 10.13