A lot of powerful computers were built by bunging in a powerful CPU, perhaps with extra RAM, as a coprocessor to an already-existing weak computer, whose weak CPU then serves as a sort of front end processor, or FEP. An example is the Tandy Model 16, which was the second line of desktop Unix workstations ever released (and arguably the first affordable one, for multi-kilobuck values of "affordable"). It was basically a Tandy Model II Z80-based computer with a daughtercard carrying a 68000 processor and up to 512 KiB of RAM. The 68000 actually ran the Unix (Microsoft Xenix), and delegated I/O to the various peripherals to the Z80.