86Box

86Box emulates historic x86 PCs at the hardware level, from the original IBM PC 5150 through Pentium II and Celeron era machines. Instead of a generic virtual machine, you pick a specific motherboard and add period video cards, sound cards, network adapters and disk controllers, which makes it useful for running MS-DOS, old Windows versions, OS/2, early Linux and software that depends on exact hardware behaviour.

A built-in manager keeps several emulated machines side by side. The emulator needs a set of ROM dumps from real hardware that is downloaded separately from the project's roms repository; without it, machines will not start.

The macOS download is a universal build for Apple silicon and Intel Macs and requires macOS 10.14 or later. Most emulation runs on a single thread, so a fast processor matters more than core count.