Intel 700 series

Intel 700 series
Name	Intel 700 series
Produced	1971–1974
Designer	Intel
Predecessor	Intel 4004
Successor	Intel 8080
Data-width	8-bit
Address-width	14-bit
Instructions	66
Transistors	3,500 to 4,800
Process	10 µm
Package	18-pin DIP

Intel 700 series. The Intel 700 series is a family of early 8-bit microprocessors introduced by Intel Corporation between 1971 and 1974. It represents a significant evolutionary step from the pioneering Intel 4004 and served as a foundational technology for early microcomputers and control systems. The series is most famously represented by the Intel 8008, though it also includes several other related processors and support chips.

Overview

The development of the series was initiated by a request from Computer Terminal Corporation (CTC) for a chip to power their Datapoint 2200 programmable terminal. Although CTC ultimately did not adopt the final design, Intel proceeded with its own commercial release. The series marked a transition from 4-bit to 8-bit architectures, enabling more complex data handling and a larger address space. Its introduction coincided with the rise of the microprocessor as a key component in embedded systems and helped establish Intel as a leader in the semiconductor industry, paving the way for the seminal Intel 8080.

Features

Key features of the series included an 8-bit data bus and a 14-bit address bus, allowing direct access to 16 KB of memory. The instruction set contained 66 instructions and supported both binary-coded decimal (BCD) and ASCII data formats. Processors in the family utilized a multi-phase clock signal, typically supplied by an external clock generator chip. They employed a stack-based architecture for subroutine calls and required multiple support components, such as the ROM and RAM chips from the same family, to form a complete system. This modular design was characteristic of early microprocessor development.

Processor list

The central processor in the series was the Intel 8008, released in April 1972. An enhanced version, the Intel 8008-1, operated at a slightly higher clock speed. The family also included several support processors: the Intel 8001 was a programmable ROM with an integrated clock generator, the Intel 8002 was a mask-programmable ROM, and the Intel 8003 was a static RAM chip. These components were designed to work together within the MCS-8 (Microcomputer System 8) ecosystem. Production of these chips was eventually superseded by more integrated designs from Intel and competitors like Motorola.

Architecture

The architecture was a von Neumann design where instructions and data shared the same bus. It featured seven 8-bit registers and an accumulator, with an external stack implemented in main memory. Instruction execution was serialized and relatively slow, often requiring multiple clock cycles per machine cycle. The interrupt handling was rudimentary, and the processor's performance was heavily dependent on the speed of its supporting memory chips. This design influenced subsequent architectures, including the more efficient Intel 8080 and the Zilog Z80.

Chipsets

A complete system required a chipset comprising several components. The Intel 8001 or a standard clock driver provided the necessary timing signals. ROM for program storage was provided by the Intel 8002, while the Intel 8003 supplied RAM for data. Additional standard TTL logic chips were needed for address latching and bus control, as the processors lacked these integrated functions. This multi-chip approach was common before the advent of microcontrollers and highly integrated microprocessors like the MOS Technology 6502.

Successor

The direct and vastly improved successor to the 700 series was the Intel 8080, introduced in 1974. The Intel 8080 featured a more advanced instruction set, a true 16-bit address bus for 64 KB of memory, and required only a single +5V power supply. It formed the heart of many landmark machines, including the Altair 8800 and early systems from IMSAI. The architectural lineage continued through the Intel 8085 and ultimately into the x86 architecture, which powered the IBM Personal Computer and defined modern personal computing.

Category:Intel microprocessors Category:8-bit microprocessors Category:1971 introductions