The MACSS aimed to develop an entirely new architecture without backward compatibility with the 6800. It ultimately does retain a bus protocol compatibility mode for existing 6800 peripheral devices, and a version with an 8-bit data bus was produced. However, the designers mainly focused on the future, or forward compatibility, which gives the 68000 design a head start against later 32-bit instruction set architectures (ISAs). For instance, the CPU registers are 32 bits wide, though few self-contained structures in the processor itself operate on 32 bits at a time. The MACSS team drew heavily on the influence of minicomputer processor design, such as the PDP-11 and VAX systems, which are similarly microcode-based.