Rockwell PPS-4
Rockwell PPS-4 in a Sharp PC. PPS-4 (part 10660) on the upper-right corner along with the 10706 clock generator, GP I/O 10696, ROM (A05xx), RAM (10432), and a 7400 series 74154 decoder.
Developer	Rockwell International
Manufacturer	Rockwell International
Production	August, 1972-1981
Architecture	4-bit words, 8-bit instruction
Word size	4-bit "-bit" is not declared as a valid unit of measurement for this property.
Clock	198.864 kHz
Package	QIL42

The PPS-4 (Parallel Processing System - 4-bit word) was a family of 4-bit microprocessor chips designed by Rockwell International and introduce in 3rd quarter of 1972.

The original PPS-4 chipset was designed to provide complete functionality in three chips - CPU, program memory, and a clock generator. A later version known as the PPS-4/2 ("/2" denoting a two-chip system) eliminated the external clock generator chip by incorporating it internally. A third variation known as the PPS-4/1 ("/1" being a single-chip microcomputer) was actually a microcontroller, including the program memory internally.