Recently my Apple collection got an over 20 years younger addition - a Mac Mini A1283 with Intel Core Duo CPU. This is my first macOS 10 machine, until now my favorite was macOS 6.0.8. Now it took me two days to get macOS 10.11 El Capitain running on this machine. Skip the next paragraph for the LisaEM bug report.
Apple sees no reason to create macOS installation media from Windows or Linux. There is no ISO file available, instead you have to run a program on a second Mac from the appropriate era to create a bootable USB drive. And it will boot. But macOS will not install because the "installation files cannot be verified". Yes, they use certificates for the EFI secure boot. And those certificates expired in 2019. So first I had to get Snow Leopard 10.6, which doesn't use Secure Boot yet, install it on the Mac Mini, and apply all available updates. Then I set the date to October 24, 2019, downloaded the El Capitain installer from Apple's support site, unplugged the LAN cable, and finally started the installation. The combination of download date, machine time, and signatures in the installer file is critical and must match.
But now I have one good use for this modern machine in my museum: running LisaEM! Installation worked fine, configuration worked fine, but every time I want to boot anything, I get the fatal error "
cpu68k_makeipclist: But! ipc is null! Stopped at cpu68k.c:cpu68k_makeipclist:1064 with code:501"
This is 1.2.7-RC4_2022.04.01 running on MacOS 10.11.6 (Core 2 Duo 2 GHz 8 GB). First I tried the dedicated installer for 10.11, then the fat one. Both installations behave the same.
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Update: same applies to RC3a, but line 1085 instead of 1064.