I've attempted to boot TempleOS on modern hardware and it does in fact fail, as TempleOS is hardcoded for IDE only. It doesn't support AHCI and has issues with SATA controllers, something that just about any 64 bit computer is going to use. It also doesn't work properly on computers without both PS/2 ports, which means tons of newer systems are out of the question. Terry ends up blaming the CIA niggers for this instead of simply adding in support for hardware that just about every single computer supports now.I very vividly remember him saying "dual boot" but honestly I wouldn't be surprised if he backpeddeled to saying it needs a VM because the CIA niggers made computers too advanced to run TOS. Like other here have said it probably can't even boot on modern hardware anymore (probably isn't compatible with UEFI, yet another universal standard he refuses to support because "God said so")
Terry himself runs it in a VM, as he begs for the computer industry to cater to his OS, not the other away around.