As above, I'm desperate to create another startup drive to be able to use foley for FCP7. I hadn't realised that High Sierra would stop working with FCP7 and hadn't transferred some projects over.
I have downloaded el capitan and created a disc image one an external HD, I also have a blank Internal HD in one of my other bays in machine but (sorry Im not massively technical) I'm not sure how to go about creating a brand new startup disk. Any help would be greatly appreciated as I'm not quite sure how to do and don't want to end up causing any problems on my current master HD.
Thanks in advance for any replies.