The F-14's Central Air Data Computer, also abbreviated as CADC, computes altitude, vertical speed, air speed, and mach number from sensor inputs such as pitot and static pressure and temperature. [1] From 1968 to 1970, the first CADC to use custom digital integrated circuits was developed for the F-14. [2]
The CADC was a multi-chip integrated flight control system developed by Garrett AiResearch and used in early versions of the US Navy's F-14 Tomcat fighter. It is notable for early use of MOS custom integrated circuits and has been claimed as the first microprocessor chipset. [2] The first commercial microprocessor chip was the contemporary Intel 4004. The 4004 did not have nearly the computing power or interfacing capability required to perform the functions of the CADC. At the time, the best integrated circuit (chip) technology available lacked the scale (number of transistors per chip) necessary to build a single-chip microprocessor for a flight control system.
The CADC was designed and built by a team led by Steve Geller and Ray Holt, and supported by the startup American Microsystems. Design work started in 1968 and was completed in June 1970, beating a number of electromechanical systems that had also been designed for the F-14. It was classified by the Navy [3] until 1998. Ray Holt's story of this design and development is presented in his autobiography The Accidental Engineer. [2]
In 1971, Holt wrote an article about the system for Computer Design magazine. [4] The Navy classified it, and released it in 1998.
The CADC consisted of an analog-to-digital converter, several quartz pressure sensors, and a number of MOS-based microchips. Inputs to the system included the primary flight controls, a number of switches, static and dynamic air pressure (for calculating stall points and aircraft speed) and a temperature gauge. The outputs controlled the wing sweep and the maneuver flaps and slats and limited allowable control inputs. [5]
The CADC's MP944 chip set ran at 375 kHz, executing 9375 instructions per second and was based on a 20-bit fixed-point-fraction two's complement number system. The complete 28-chip system enabled by 74,442 transistors [6] used the following 6 unique dual in-line package (DIP) chips:
| Chip name | Abbreviation | Pin count | Purpose | Number of chips used in the system |
|---|---|---|---|---|
| Read-only memory | ROM | 14 | provides instructions and constants | 19 |
| Steering logic unit | SLU | 28 | decodes instructions and routes data into a computation unit | 3 |
| Parallel multiplier unit | PMU | 28 | computation unit | 1 |
| Parallel divider unit | PDU | 28 | computation unit | 1 |
| Special logic function | SLF | 28 | computation unit | 1 |
| Random-access storage | RAS | 14 | stores data from its computation unit | 3 |
The system arranges these chips into 3 modules. Each module consists of a set of ROMs which serially send microinstructions and constants to that module's SLU, which routes data inputs to that module's computation unit (either a PMU, a PDU, or a SLF), whose results are written into that module's RAS and routed via the SLUs to any module. Each module forms its own pipeline and can be used without the others. This made it easy to expand the system with additional modules. Multiple pipelines worked at the same time, a parallel computing technique called "pipeline concurrency". The ROM stores 128 words of 20-bits each. A register counter in ROM can be reset, step through the words in sequence, accept a retain address command and hold the present address, and accept a numerical input for address modifying or loading. [4]
An integrated circuit (IC), also known as a microchip or simply chip, is a small electronic device made up of multiple interconnected electronic components such as transistors, resistors, and capacitors. These components are etched onto a small piece of semiconductor material, usually silicon. Integrated circuits are used in a wide range of electronic devices, including computers, smartphones, and televisions, to perform various functions such as processing and storing information. They have greatly impacted the field of electronics by enabling device miniaturization and enhanced functionality.
A microprocessor is a computer processor for which the data processing logic and control is included on a single integrated circuit (IC), or a small number of ICs. The microprocessor contains the arithmetic, logic, and control circuitry required to perform the functions of a computer's central processing unit (CPU). The IC is capable of interpreting and executing program instructions and performing arithmetic operations. The microprocessor is a multipurpose, clock-driven, register-based, digital integrated circuit that accepts binary data as input, processes it according to instructions stored in its memory, and provides results as output. Microprocessors contain both combinational logic and sequential digital logic, and operate on numbers and symbols represented in the binary number system.
The 6800 is an 8-bit microprocessor designed and first manufactured by Motorola in 1974. The MC6800 microprocessor was part of the M6800 Microcomputer System that also included serial and parallel interface ICs, RAM, ROM and other support chips. A significant design feature was that the M6800 family of ICs required only a single five-volt power supply at a time when most other microprocessors required three voltages. The M6800 Microcomputer System was announced in March 1974 and was in full production by the end of that year.
A microcontroller or microcontroller unit (MCU) is a small computer on a single integrated circuit. A microcontroller contains one or more CPUs along with memory and programmable input/output peripherals. Program memory in the form of NOR flash, OTP ROM, or ferroelectric RAM is also often included on the chip, as well as a small amount of RAM. Microcontrollers are designed for embedded applications, in contrast to the microprocessors used in personal computers or other general-purpose applications consisting of various discrete chips.
Very-large-scale integration (VLSI) is the process of creating an integrated circuit (IC) by combining millions or billions of MOS transistors onto a single chip. VLSI began in the 1970s when MOS integrated circuit chips were developed and then widely adopted, enabling complex semiconductor and telecommunications technologies. The microprocessor and memory chips are VLSI devices.
An embedded system is a specialized computer system—a combination of a computer processor, computer memory, and input/output peripheral devices—that has a dedicated function within a larger mechanical or electronic system. It is embedded as part of a complete device often including electrical or electronic hardware and mechanical parts. Because an embedded system typically controls physical operations of the machine that it is embedded within, it often has real-time computing constraints. Embedded systems control many devices in common use. In 2009, it was estimated that ninety-eight percent of all microprocessors manufactured were used in embedded systems.
Jay Glenn Miner was an American integrated circuit designer, known primarily for developing graphics and audio chips for the Atari 2600 and Atari 8-bit computers and as the "father of the Amiga".
A system on a chip or system-on-chip is an integrated circuit that integrates most or all components of a computer or electronic system. These components usually include an on-chip central processing unit (CPU), memory interfaces, input/output devices and interfaces, and secondary storage interfaces, often alongside other components such as radio modems and a graphics processing unit (GPU) – all on a single substrate or microchip. SoCs may contain digital and also analog, mixed-signal and often radio frequency signal processing functions.
The Intel 4004 is a 4-bit central processing unit (CPU) released by Intel Corporation in 1971. Sold for US$60, it was the first commercially produced microprocessor, and the first in a long line of Intel CPUs.
The history of computing hardware starting at 1960 is marked by the conversion from vacuum tube to solid-state devices such as transistors and then integrated circuit (IC) chips. Around 1953 to 1959, discrete transistors started being considered sufficiently reliable and economical that they made further vacuum tube computers uncompetitive. Metal–oxide–semiconductor (MOS) large-scale integration (LSI) technology subsequently led to the development of semiconductor memory in the mid-to-late 1960s and then the microprocessor in the early 1970s. This led to primary computer memory moving away from magnetic-core memory devices to solid-state static and dynamic semiconductor memory, which greatly reduced the cost, size, and power consumption of computers. These advances led to the miniaturized personal computer (PC) in the 1970s, starting with home computers and desktop computers, followed by laptops and then mobile computers over the next several decades.
Federico Faggin is an Italian-American physicist, engineer, inventor and entrepreneur. He is best known for designing the first commercial microprocessor, the Intel 4004. He led the 4004 (MCS-4) project and the design group during the first five years of Intel's microprocessor effort. Faggin also created, while working at Fairchild Semiconductor in 1968, the self-aligned MOS (metal–oxide–semiconductor) silicon-gate technology (SGT), which made possible MOS semiconductor memory chips, CCD image sensors, and the microprocessor. After the 4004, he led development of the Intel 8008 and 8080, using his SGT methodology for random logic chip design, which was essential to the creation of early Intel microprocessors. He was co-founder and CEO of Zilog, the first company solely dedicated to microprocessors, and led the development of the Zilog Z80 and Z8 processors. He was later the co-founder and CEO of Cygnet Technologies, and then Synaptics.
Masatoshi Shima is a Japanese electronics engineer. He was one of the architects of the world's first microprocessor, the Intel 4004. In 1968, Shima worked for Busicom in Japan, and did the logic design for a specialized CPU to be translated into three-chip custom chips. In 1969, he worked with Intel's Ted Hoff and Stanley Mazor to reduce the three-chip Busicom proposal into a one-chip architecture. In 1970, that architecture was transformed into a silicon chip, the Intel 4004, by Federico Faggin, with Shima's assistance in logic design.
In computer engineering, a logic family is one of two related concepts:
The transistor count is the number of transistors in an electronic device. It is the most common measure of integrated circuit complexity. The rate at which MOS transistor counts have increased generally follows Moore's law, which observes that transistor count doubles approximately every two years. However, being directly proportional to the area of a die, transistor count does not represent how advanced the corresponding manufacturing technology is. A better indication of this is transistor density which is the ratio of a semiconductor's transistor count to its die area.
A computer is a machine that can be programmed to automatically carry out sequences of arithmetic or logical operations (computation). Modern digital electronic computers can perform generic sets of operations known as programs. These programs enable computers to perform a wide range of tasks. The term computer system may refer to a nominally complete computer that includes the hardware, operating system, software, and peripheral equipment needed and used for full operation; or to a group of computers that are linked and function together, such as a computer network or computer cluster.
Four-phase logic is a type of, and design methodology for dynamic logic. It enabled non-specialist engineers to design quite complex ICs, using either PMOS or NMOS processes. It uses a kind of 4-phase clock signal.
PMOS or pMOS logic is a family of digital circuits based on p-channel, enhancement mode metal–oxide–semiconductor field-effect transistors (MOSFETs). In the late 1960s and early 1970s, PMOS logic was the dominant semiconductor technology for large-scale integrated circuits before being superseded by NMOS and CMOS devices.
This article details the history of electronics engineering. Chambers Twentieth Century Dictionary (1972) defines electronics as "The science and technology of the conduction of electricity in a vacuum, a gas, or a semiconductor, and devices based thereon".