|Rockwell PPS-4 found in the PC-1001 programmable calculator. 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.|
|Architecture||4-bit words, 8-bit instruction|
|Word size|| 4 bit|
|Clock||40 kHz-256 kHz|
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.
|10660||CPU||Original "PPS-4" CPU|
|12660||CPU||Same as 10660|
|10686||General purpose I/O|
|10696||General purpose I/O|
|10731||com data interface|
|10736||dot matrix printer controller|
|10930||serial data controller|
|15380||dot matrix printer controller|
National semiconductor later became a second source for the PPS-4.
While not as known as the other chips like the MCS-4, the PPS-4 certainly never received as much mainstream exposure. Nevertheless, it did find its way into many industrial and consumer products such as toys, desktop calculators, games, and other electronic appliances.