Linux enthusiasts who still own a vintage Macintosh machine with a Motorola 68020, 030, or 040 CPU and an MMU will be delighted to know that a new release of the developmental branch of Linux/m68k port is now available for download. The version 4.14.309 Test kernel can be found on the project’s official website, The Linux/m68k for Macintosh.
The project’s objective is to enhance the Linux support for 68k-based Macintoshes and its related hardware. Almost all Macs with a 68030 or better processor are usable in some form under Linux/mac68k. A 68020 CPU with 68851 PMMU should also work. However, older 68000-based Macs are not supported yet. The team is still working on the development of support for specific hardware devices. More information on hardware support can be found on the machine status page.
The developmental branch of the Linux/m68k port caters to older Macintosh machines, including those with 68020, 030, or 040 CPUs and MMU, which include most II/LC/Centris/Quadra/Performa-class machines. The website also provides a status page for hardware compatibility information.
The 68040-based Macintosh machines with a built-in FPU and the 68LC040-based models fitted with late revision CPUs are supported. The 68030-based models and the 68020-based machines fitted with a PMMU are also supported. However, early revisions of the 68LC040 chip may have a flaw that affects the kernel’s capability to handle exceptions correctly, which impacts demand paging in the presence of FPU operations. Users can check if their Mac’s CPU is affected by booting a special test kernel available for download.
In order to run Linux on a 68020-based Macintosh machine, users will need to acquire a 68851 PMMU chip to enable the paged memory that Linux and A/UX require. Of the two 68020 models, only the Mac II supports the addition of a PMMU. The other model, the Mac LC, does not have this capability and is, therefore, not supported.
For those who are searching for Linux for the PowerPC, the mainline Linux support comes in the form of Linux/PPC, also known as PenguinPPC. This port only supports PCI-based PowerMacs. A separate port is available for NuBus PowerMacs.
For more information and to download Linux/Mac68K, visit the project’s website at http://mac.linux-m68k.org.
