The "Peripheral Processor" was a separate system dedicated entirely to quickly running the operating system and programs running within it, as well as feeding data to the CPU. The PP was built out of eight "virtual processors" (VPs), which were designed to handle instructions and basic integer arithmetic only. Each VP had its own program counter and registers, and the system could thus run eight programs at the same time, limited only by memory accesses. Keeping eight programs running allowed the system to shuffle execution of programs on the CPU depending on what data was available on the memory bus at that time, minimizing "dead time" where the CPU had to wait for data from the memory.