how to create bootable macos high sierra usb

Use the High Sierra bootable USB to install on the new empty drive in my other MBP ( note : I tried to build one for Mojave but apparently that's not supported on my A1278 either.) Use my working High Sierra MBP to create an otherwise pointless 'High Sierra bootable USB' The only viable method I have come up with is (I think) the following: This is a completely ******** decision by Apple not to provide any sensible options for downloading and creating offline media FOR different versions of MacOS to the one you're running! The 'help' for that particular command doesn't help me understand and doesn't match what I read online, so I guess what I'm reading online caters ONLY for Catalina terminal app :(

Softwareupdate: unrecognized option `-full-installer-version' Softwareupdate: unrecognized option `-fetch-full-installer' Softwareupdate -fetch-full-installer -full-installer-version 10.15.3 I found a link that suggested terminal commands like: I'm not interested in running unvetted third-party tools like that - don't trust them.ĭoes anyone know how I can manually DOWNLOAD and create a bootable USB Catalina installer from my working High Sierra MBP? I am aware of unsupported methods such as 'catalina patcher' that allow installing/upgrading on Macs that would otherwise fail Apple's compatibility checks. No other devices have been conducting 'high usage' activities while I'm trying to perform the internet recovery. I have a very fast fibre connection, and there is no firewall on outbound comms, I am using WiFi but have no method of plugging this newer MBP in with a cable to eliminate WiFi use. I have tried around a dozen times to perform Internet Recovery on the newer MBP with new drive - it always stops after I have hit 'continue' on the install Catalina link after a minute or so with 'could not contact a recovery server' This is of course a flawed assumption since I have NO intention of installing it ON the Mac I'm trying to download from. I have gone round in silly circles with App Store, it seems 'Apple knows best' and refuse to let me download the installer since I'm doing it on an unsupported Mac. How ON EARTH can I use my functional (but outdated and unsupported) Mac to download and create a bootable USB for Catalina to rebuild my supported MBP? The OTHER one does NOT support Catalina, it's too old (A1278), it's running macOS High Sierra 10.13.6.

One supports Catalina (A1398) - but the drive died and I have replaced with a new, empty drive.

How to create bootable macos high sierra usb