Chapter in this post:
With Apple's Mac operating system macOS 10.15 Catalina, only 64-bit apps can be used. Software with 32-bit architecture can no longer be used by default. However, there are one or two tricks with which the "old" apps can still be used - even if Catalina is your primary OS on the Mac. In this little guide I have summarized a few ways that you can go for it.
With the APFS file system on the Mac, it becomes unnecessary to create a new partition to install a second version of macOS. It is sufficient to create what is known as an APFS volume. A predefined storage space does not necessarily have to be reserved for this; it grows with you, so to speak - unless you limit it manually. To create an APFS volume, you simply proceed as follows:
After you have created the new "virtual hard disk", start the macOS installer of your choice (High Sierra or Mojave; or Catalina, if one of the previous ones is your primary OS). Instead of the Macintosh HD or your differently named main hard drive, choose the volume created after the above steps as the installation target. To do this, you probably have to click on "Show all volumes ..." and bring it into the overview. The installation is carried out quite normally as with other Mac operating systems on the Apple computer.
Here are two blog posts and a collection of instructions as further reading:
With the above solution, you have the advantage that you use a proprietary function and no third-party app is required. It looks different if you want to run and use both operating systems at the same time - like Windows under Parallels Desktop. For example, if you want to run Mojave in a virtual machine while using Catalina, then you need for example Parallels Desktop 15. This version of the well-known VM software not only brings Windows apps to the iPad via Sidecar, but also Mojave to the Catalina computer, so that 32-bit apps can continue to be used.
A free alternative that you have to dig into: ORACLE VirtualBox.
So if a 32-bit app on your Mac that you have updated to macOS 10.15 Catalina is no longer running, you still have the option of using it in a roundabout way. The best, most time-saving and resource-saving variant is of course to update the app to a 64-bit version. In case of doubt, you can ask the developer whether or when this is possible. So if there is no notice on its website and the program does not offer any updates via its interface, just write an email;)
In addition to apps, other software will of course also be affected by the changeover; for example drivers for scanners, printers, multifunctional units, document scanners and the like. Here in the blog I have recently shown you two or three solutions for scanner devices that can be the salvation for hundreds of models for use with Catalina. They are suitable for private users, the self-employed and companies:
Jens has been running the blog since 2012. He appears as Sir Apfelot for his readers and helps them with problems of a technical nature. In his free time he drives electric unicycles, takes photos (preferably with his iPhone, of course), climbs around in the Hessian mountains or hikes with the family. His articles deal with Apple products, news from the world of drones or solutions for current bugs.