function

- CPU (Single-Chip Central Processing Unit);
  consists of Control Unit and Arithmetic + Logic Unit

- Microcontroller (Single-Chip Microcomputer);
  consists of ROM, RAM, CPU and I/O logic in one single package

- Bit Slice Processor; Arithmetic + Logic Unit of CPU (ALU)
  The Bit-slice microprocessor design has three very significant advantages:

1. ALU's can be used in a horizontal configuration to create computers that can handle very large chunks of data at a time.

2. The two chip design allowed the chips to use bipolar chip technology. Bipolar is very fast, but consumes lots of power and dissipates lots of heat. Because of the heat dissipation problem, bipolar chips could not be as dense (in number of transistors per area) as the PMOS or NMOS chips. It was not possible to build single-chip CPU's using bipolar technology. So, in addition to the wider data paths the Bit-slice devices could achieve, they were inherently faster due the bipolar technology that was employed to build the chips.

3. Ability to allow users to create their own instruction sets for their applications. Instructions sets could be created to emulate, or enhance, existing processors such as the 6502 or 8080, or to create a unique instruction set specially adapted to maximize performance of a specific application. The combination of the speed and flexibility of Bit-slice devices made the very popular and created a cult-like following.