Creating a USB Flash Drive Installer from a Snow Leopard ISO File This was tested using an iMac (21.5-inch, Mid 2011) 2.5 GHz Intel Core i5 with MacOS High Sierra 10.13.6 installed. The procedure should be the same for Catalina. Jun 18, 2017 Create a multi-macOS bootable USB. In this post I will be showing you how to partition your USB stick and make it bootable with 8 versions of macOS. Starting from Snow Leopard all the way to the newly released macOS 10.13 High Sierra Developer Beta 1. In fact, I'm still on Snow Leopard (MacOS X 10.6.8). This is a version so old that all the steps I read to make a bootable USB drive failed. I wasn't able to use createinstallmedia to make a boot disk because that doesn't work until MacOS X 10.7.
Not tried this so it may/may not work. If you go into System Prefs (on your new iMac) and enable DVD or CD sharing in the 'Sharing' folder, you may, in the sidebar of your old MacBook be able to see the iMac's CD drive. Putting the install DVD in the iMac then allows you to install onto the MacBook if it all works OK, but as I say not sure of compatibility or features available in Leopard etc and have also just thought you may be installing onto a newly formatted drive in the macBook so won't see anything but could be worth trying. Hope that helps.
Feb 20, 2017 1:35 AM