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machenryr

macrumors 6502a
Original poster
Jan 25, 2016
748
101
I can't remember how to do this. I have three Mac Pros: my main one is the 2019 7,1. Then I have two older 2010 5,1. I'd been networking one daily. But the third one has been in another room unused, until today.

The last time I used MacPro 3 I rebooted into Sierra to retrieve some older files, but it was functioning under Catalina.
Mac Pro 2 is High Sierra, while my main 7,1 is Big Sur.

I can't boot into Mac Pro 3 Catalina. There's a trick to doing this but I don't recall what it is. Every time I try it boots into the Sierra drive. Do I have to attach a mouse and monitor and boot into the Catalina SSD before I can boot using network? Thanks!
 

machenryr

macrumors 6502a
Original poster
Jan 25, 2016
748
101
As I recall I can't boot from Sierra to Catalina? So I have to boot from High Sierra then into Catalina?
 

machenryr

macrumors 6502a
Original poster
Jan 25, 2016
748
101
I guess I don't have the problem I thought I did. Never mind. LOL
 
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