firmware update and 10.6

[WayneStewart]

Since the public version just came out and anything written about the beta versions may not apply, I’m wondering if I install 10.13 with the firmware update to my 2010 Mac Pro, will that affect my ability to boot 10.6 off another internal HD?

 

[chrfr]

Since the public version just came out and anything written about the beta versions may not apply, I’m wondering if I install 10.13 with the firmware update to my 2010 Mac Pro, will that affect my ability to boot 10.6 off another internal HD?

No, it won't affect that at all.

 

[LightBulbFun]

if you dig around in the APFS thread theres a post where I booted Leopard 10.5.8 from my Mac Pro running the updated firmware

 

[WayneStewart]

Thanks, that answers my concerns.
I'll try the 10.13 install tonight