Just so you know: trying to boot the High Sierra installer on a 2019 Mac is very likely to present you with the following screen, which means "This version of macOS isn't compatible with this Mac."
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Running old OSX on EHD
- Thread starter sunnyjohn2
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Many thanks. So to get back to my original post:
I've some old 32 bit apps that I want to run on an older version of OSX. I've managed to download High Sierra to a DMG but the installer won't open on my Big Sur. Is there any way I can get the High Sierra DMG onto my EHD so that it will download High Sierra on the HD?
I've some old 32 bit apps that I want to run on an older version of OSX. I've managed to download High Sierra to a DMG but the installer won't open on my Big Sur. Is there any way I can get the High Sierra DMG onto my EHD so that it will download High Sierra on the HD?
Your only option is to virtualise High Sierra using e.g. Parallels Desktop or VMware Fusion. I think both products are available in a free edition. When creating a VM, pointing the assistant at the Install macOS High Sierra application you're currently downloading may be sufficient.
That's brilliant! Many thanks. I've already set up a machine for High Sierra in VirtualBox, so as soon as it's downloaded (40 mins to go!), I'll give it a go. Thanks for your patience!
Mojave will run 32 bit aps and it will boot your 2019 iMac. Download that and install it on your EHD.
Here are some links that should help:
How to download and install macOS - Apple Support
Download and install current or previous versions of the Mac operating system on compatible Mac computers.
How to Download macOS Sequoia, Sonoma, Ventura, Monterey, Big Sur, Catalina & Mojave Full Installers
How to download macOS Monterey, Big Sur, Catalina, Mojave, High Sierra, Sierra, El Capitan, Yosemite, Mavericks, Mountain Lion & Lion 7 ways!
mrmacintosh.com
You'll (probably) have to convert the downloaded High Sierra installer into an ISO file for VirtualBox to be able to boot it. This is described at the beginning of this guide.
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AFAIK, Parallels has a free trial but after that you must either purchase the standalone version or subscribe for the Pro version. At least, that was the case when I got it in 2020. I believe that Fusion has a free version with some limitations, not sure of those limits would be a problem for what you want.
As I posted earlier, I really like using Parallels for legacy MacOS apps since they integrate with your current MacOS version like any other apps and don't require a re-boot, etc. The apps I use (VectorWorks, FileMaker Pro, Strata 3dcx) all run much faster in a VM than they did on my old Macs.
Thanks for reminding me. I did that with Windows 10 and successfully got an ISO which went onto a disk, so I can run Windows. I'll have forgotten how to do it, so thanks for the tip and the link.
Mojave will run 32 bit aps and it will boot your 2019 iMac. Download that and install it on your EHD.
Here are some links that should help:
How to download and install macOS - Apple Support
Download and install current or previous versions of the Mac operating system on compatible Mac computers.support.apple.com
How to Download macOS Sequoia, Sonoma, Ventura, Monterey, Big Sur, Catalina & Mojave Full Installers
How to download macOS Monterey, Big Sur, Catalina, Mojave, High Sierra, Sierra, El Capitan, Yosemite, Mavericks, Mountain Lion & Lion 7 ways!
No- you can't get installers from the Apple Store anymore. All those links are now out-of-date!Mojave will run 32 bit aps and it will boot your 2019 iMac. Download that and install it on your EHD.
Here are some links that should help:
How to download and install macOS - Apple Support
Download and install current or previous versions of the Mac operating system on compatible Mac computers.How to Download macOS Sequoia, Sonoma, Ventura, Monterey, Big Sur, Catalina & Mojave Full Installers
How to download macOS Monterey, Big Sur, Catalina, Mojave, High Sierra, Sierra, El Capitan, Yosemite, Mavericks, Mountain Lion & Lion 7 ways!
Sorry, never looked into those. I needed the features of the Pro version for running a 32gb/4 core Windows 10 machine. They sound like they would be worth checking out.
As is VirtualBox and I've had no trouble using that with Windows 10 on my Mac.
I use VirtualBox myself. It’s awesomely configurable and flexible.
There’s also a version of the tool I linked to that will download a Mojave installer straight from Apple’s servers. If you want to go down that route…
It might be easier to get the Mojave installer. Can you give me a link to the tool?
Thanks again. I'll get the High Sierra DMG down first, then give Mojave a go. You're a star!
The links were working earlier this morning, but Apple is having network problems which is currently impacting the App Store among others.
See the current MacRumors thread:
iCloud and Many Other Apple Services Are Down or Experiencing Issues [Resolved]
Apple is experiencing a widespread outage today, with a wide range of the company's services and apps down or experiencing issues currently. Affected services and apps include the App Store, iCloud, Siri, iMessage, iTunes Store, Apple Maps, Apple Music, Apple Podcasts, Apple Arcade, Apple...
forums.macrumors.com
Thanks for this - another possibility.The links were working earlier this morning, but Apple is having network problems which is currently impacting the App Store among others.
See the current MacRumors thread:
iCloud and Many Other Apple Services Are Down or Experiencing Issues [Resolved]
Apple is experiencing a widespread outage today, with a wide range of the company's services and apps down or experiencing issues currently. Affected services and apps include the App Store, iCloud, Siri, iMessage, iTunes Store, Apple Maps, Apple Music, Apple Podcasts, Apple Arcade, Apple...
I now have the Mojave installer in my applications folder and on a USB Drive. I am unable to open Mojave on my machine - it says it's too old. How do I get Mojave on my USB into my EDD?
How to create from Terminal a bootable dmg, that can be used in a virtual machine, from the Mojave installer.
Code:
hdiutil create ~/Desktop/1014.dmg -size 8g -layout SPUD -fs HFS+J
hdiutil attach ~/Desktop/1014.dmg -noverify -nobrowse -mountpoint /Volumes/InstallMojave
sudo /Applications/Install\ macOS\ Mojave.app/Contents/Resources/createinstallmedia --volume /Volumes/InstallMojave
hdiutil detach /Volumes/Install\ macOS\ Mojave
hdiutil resize -sectors min ~/Desktop/1014.dmgDo you want to run Mojave natively (i.e. not in a virtual machine) on your iMac using your external hard drive, or in a VM?
If this is for a VM, open Terminal, execute the commands given in #45 and attach that image as secondary hard drive to the VM (the VM's primary hard drive is the one Mojave will be installed on).
If this is for a native installation, create a bootable installer on your USB stick (which must be named USBSTICK - if it isn't, change the command to match) using the following command in Terminal and boot your iMac from that. Select the external HD to install Mojave on.
sudo /Applications/Install\ macOS\ Mojave.app/Contents/Resources/createinstallmedia --volume /Volumes/USBSTICKI'm now processing an ISO for my virtual machine but I would prefer to run Mojave on my EDD. I have produced the USB as you suggested and I assume that I use disk manager to get it onto my EDD. Unfortunately, I am unable to boot to disk manager because for some reason the option key does not function. I've checked that it's working on the keyboard via the keyboard viewer and it its there all OK. I've also reset SVRAM (which actually improved the running of Big Sur) but the option key still refused to boot to disk manager. I've also checked the keyboard configuration and tried another keyboard. I've run first aid on my hard disk and all is OK. I'm now about to try recovery and see if that will fix it.
Is it labelled “Install macOS Mojave” or something like that now?
You said your [Option] key doesn’t work at boot-up. Are you using an Apple keyboard?
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