The Intel CPU chip used in first-generation IBM PCs (XT class). It was the brother of the 16-bit 8086 chip, but only the CPU was 16 bits. The data bus was 8 bits. This configuration was chosen by IBM to encourage migration from the 8-bit CP/M environment to DOS. CP/M was the predominant operating system for business applications in the early 1980s. See 8086, x86 and CPM. Technical Specs Type: 16-bit multitasking microprocessor; 8-bit bus Transistors: 25,000 Package: 40-pin CERDIP Registers: 14 16-bit Addressing mode (later called Real Mode): Addresses 1MB memory.