The Intel 8080 ("eighty-eighty") is the second 8-bit microprocessor designed and manufactured by Intel. It first appeared in April 1974 and is an extended and enhanced variant of the earlier 8008 design, although without binary compatibility. The initial specified clock rate or frequency limit was 2 MHz, with common instructions using 4, 5, 7, 10, or 11 clock cycles. As a result, the processor is able to execute several hundred thousand instructions per second. Two faster variants, the 8080A-1 and 8080A-2, became available later with clock frequency limits of 3.125 MHz and 2.63 MHz respectively. The 8080 needs two support chips to function in most applications: the i8224 clock generator/driver and the i8228 bus controller. The 8080 is implemented in N-type metal–oxide–semiconductor logic (NMOS) using non-saturated enhancement mode transistors as loads thus demanding a +12 V and a −5 V voltage in addition to the main transistor–transistor logic (TTL) compatible +5 V.
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 Motorola 68000 is a 16/32-bit complex instruction set computer (CISC) microprocessor, introduced in 1979 by Motorola Semiconductor Products Sector.
The MOS Technology 6502 is an 8-bit microprocessor that was designed by a small team led by Chuck Peddle for MOS Technology. The design team had formerly worked at Motorola on the Motorola 6800 project; the 6502 is essentially a simplified, less expensive and faster version of that design.
The Zilog Z80 is an 8-bit microprocessor designed by Zilog that played an important role in the evolution of early computing. Software-compatible with the Intel 8080, it offered a compelling alternative due to its better integration and increased performance. The Z80 boasted fourteen registers compared to the 8080's seven, along with additional instructions for bit manipulation, making it a more powerful chip.
The NS32000, sometimes known as the 32k, is a series of microprocessors produced by National Semiconductor. The first member of the family came to market in 1982, briefly known as the 16032 before becoming the 32016. It was the first general-purpose microprocessor on the market that used 32-bit data internally: the Motorola 68000 had 32-bit registers and instructions to perform 32-bit arithmetic, but used a 16-bit ALU for arithmetic operations on data, and thus took twice as long to perform those arithmetic operations. However, the 32016 contained many bugs and often could not be run at its rated speed. These problems, and the presence of the otherwise similar 68000 which had been available since 1980, led to little use in the market.
4-bit computing is the use of computer architectures in which integers and other data units are 4 bits wide. 4-bit central processing unit (CPU) and arithmetic logic unit (ALU) architectures are those that are based on registers or data buses of that size. A group of four bits is also called a nibble and has 24 = 16 possible values, with a range of 0 to 15.
Bit slicing is a technique for constructing a processor from modules of processors of smaller bit width, for the purpose of increasing the word length; in theory to make an arbitrary n-bit central processing unit (CPU). Each of these component modules processes one bit field or "slice" of an operand. The grouped processing components would then have the capability to process the chosen full word-length of a given software design.
Am2900 is a family of integrated circuits (ICs) created in 1975 by Advanced Micro Devices (AMD). They were constructed with bipolar devices, in a bit-slice topology, and were designed to be used as modular components each representing a different aspect of a computer control unit (CCU). By using the bit slicing technique, the Am2900 family was able to implement a CCU with data, addresses, and instructions to be any multiple of 4 bits by multiplying the number of ICs. One major problem with this modular technique was that it required a larger number of ICs to implement what could be done on a single CPU IC. The Am2901 chip included an arithmetic logic unit (ALU) and 16 4-bit processor register slices, and was the "core" of the series. It could count using 4 bits and implement binary operations as well as various bit-shifting operations. The Am2909 was a 4-bit-slice address sequencer that could generate 4-bit addresses on a single chip, and by using n of them, it was able to generate 4n-bit addresses. It had a stack that could store a microprogram counter up to 4 nest levels, as well as a stack pointer.
The MCP-1600 is a multi-chip 16-bit microprocessor introduced by Western Digital in 1975 and produced through the early 1980s. Used in the Pascal MicroEngine, the WD16 processor in the Alpha Microsystems AM-100, and the DEC LSI-11 microcomputer, a cost-reduced and compact implementation of the DEC PDP-11.
The history of general-purpose CPUs is a continuation of the earlier history of computing hardware.
The 74181 is a 4-bit slice arithmetic logic unit (ALU), implemented as a 7400 series TTL integrated circuit. Introduced by Texas Instruments in February 1970, it was the first complete ALU on a single chip. It was used as the arithmetic/logic core in the CPUs of many historically significant minicomputers and other devices.
National Semiconductor's IPC-16A PACE, short for "Processing and Control Element", was the first commercial single-chip 16-bit microprocessor, announced in late 1974. It was a single-chip implementation of their early 1973 five-chip IMP-16 architecture, which in turn had been inspired by the Data General Nova minicomputer. To the basic IMP-16, PACE added a new operational mode, "byte mode", which was useful for working with 8-bit data like ASCII text.
In computer architecture, 16-bit integers, memory addresses, or other data units are those that are 16 bits wide. Also, 16-bit central processing unit (CPU) and arithmetic logic unit (ALU) architectures are those that are based on registers, address buses, or data buses of that size. 16-bit microcomputers are microcomputers that use 16-bit microprocessors.
In computing, an arithmetic logic unit (ALU) is a combinational digital circuit that performs arithmetic and bitwise operations on integer binary numbers. This is in contrast to a floating-point unit (FPU), which operates on floating point numbers. It is a fundamental building block of many types of computing circuits, including the central processing unit (CPU) of computers, FPUs, and graphics processing units (GPUs).
In computer architecture, 1-bit integers or other data units are those that are 1 bit wide. Also, 1-bit central processing unit (CPU) and arithmetic logic unit (ALU) architectures are those that are based on registers of that size.
The TMS1000 is a family of microcontrollers introduced by Texas Instruments in 1974.
The Texas Instruments SBP0400, also known as SBC 0400 and X0400, is a microprogrammable 4-bit slice processor that was introduced in 1976. It was one of the first LSI processors and was the first device in the USA based on I²L technology. It was used for research and teaching purposes in the aerospace industry (NASA) and in the learning computer LCM-1001. This microprocessor learning computer was probably the company's first.
The Fairchild 9440 MICROFLAME, also known as the F9440 and μFLAME, was a 16-bit microprocessor introduced by Fairchild Semiconductor in 1977. The 9440 implemented the Data General Nova 2's instruction set in a single-chip 40-pin DIP. The name "MICROFLAME" was part of a wider branding exercise called "FIRE", which was a development software system.
The NEC μCOM series is a series of microprocessors and microcontrollers manufactured by NEC in the 1970s and 1980s. The initial entries in the series were custom-designed 4 and 16-bit designs, but later models in the series were mostly based on the Intel 8080 and Zilog Z80 8-bit designs, and later, the Intel 8086 16-bit design. Most of the line was replaced in 1984 by the NEC V20, an Intel 8088 clone.
