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The Intel 8080 (''"eighty-eighty"'') is the second
8-bit In computer architecture In computer engineering, computer architecture is a set of rules and methods that describe the functionality, organization, and implementation of computer systems. Some definitions of architecture define it as descr ...
microprocessor A microprocessor is a computer processor where the data processing logic and control is included on a single integrated circuit An integrated circuit or monolithic integrated circuit (also referred to as an IC, a chip, or a microchip ...

microprocessor
designed and manufactured by
Intel Intel Corporation is an American multinational corporation A multinational company (MNC) is a corporate A corporation is an organization—usually a group of people or a company A company, abbreviated as co., is a Legal personalit ...

Intel
. It first appeared in April 1974 and is an extended and enhanced variant of the earlier
8008
8008
design, although without
binary compatibility Binary-code compatibility (binary compatible or object-code-compatible) is a property of computer systems A computer is a machine A machine is a man-made device that uses power to apply forces and control movement to perform an action ...
.'' Electronic News'' was a weekly trade newspaper. The same advertisement appeared in the May 2, 1974 issue of ''Electronics'' magazine. The initial specified
clock rate In computing Computing is any goal-oriented activity requiring, benefiting from, or creating computing machinery. It includes the study and experimentation of algorithmic processes and development of both computer hardware , hardware and softwa ...
or frequency limit was 2 
MHz The hertz (symbol: Hz) is the derived unit of frequency Frequency is the number of occurrences of a repeating event per unit of time. It is also referred to as temporal frequency, which emphasizes the contrast to spatial frequency and an ...
, with common instructions using 4, 5, 7, 10, or 11 cycles. As a result, the processor is able to execute several hundred thousand
instructions per second Instructions per second (IPS) is a measure of a computer A computer is a machine that can be programmed to carry out sequences of arithmetic or logical operations automatically. Modern computers can perform generic sets of operations known ...
. Two faster variants, the 8080A-1 (sometimes referred to as the 8080B) 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. It is implemented in N-type metal-oxide-semiconductor logic (NMOS) using non-saturated
enhancement mode Image:FET_comparison.png, Depletion type FETs under typical voltages. JFET, poly-silicon MOSFET, double-gate MOSFET, metal gate MOSFET, MESFET.  depletion ,  electrons ,  holes ,  metal ,  insulato ...
transistors as loads thus demanding a +12 
V
V
and a −5 V voltage in addition to the main
transistor–transistor logic Transistor–transistor logic (TTL) is a logic family In computer engineering Computer engineering (CoE or CpE) is a branch of engineering Engineering is the use of scientific method, scientific principles to design and build machine ...
(TTL) compatible +5 V. Although earlier microprocessors were commonly used in mass-produced devices such as
calculator An electronic calculator is typically a portable device used to perform s, ranging from basic to complex . The first calculator was created in the early 1960s. Pocket-sized devices became available in the 1970s, especially after the , the f ...

calculator
s,
cash register 300px, Antique crank-operated cash register A cash register or till or automated money handling system is a mechanical or electronic device for registering and calculating transactions at a point of sale The point of sale (POS) or point of p ...
s,
computer terminal A computer terminal is an electronic or electromechanical hardware device that can be used for entering data into, and transcribing data from, a computer A computer is a machine that can be programmed to carry out sequences of arithmeti ...
s,
industrial robot An industrial robot is a robot A robot is a machine—especially one Computer program, programmable by a computer—capable of carrying out a complex series of actions automatically. A robot can be guided by an external control device, o ...

industrial robot
s, and other applications, the 8080 saw greater success in a wider set of applications, and is largely credited with starting the
microcomputer A microcomputer is a small, relatively inexpensive computer with a microprocessor as its central processing unit (CPU). It includes a microprocessor, Computer memory, memory and minimal input/output (I/O) circuitry mounted on a single printed ci ...
industry. Several factors contributed to its popularity: its 40-pin package made it easier to interface than the 18-pin 8008, and also made its data bus more efficient; its NMOS implementation gave it faster transistors than those of the P-type metal-oxide-semiconductor logic (PMOS) 8008, while also simplifying interfacing by making it TTL-compatible; a wider variety of support chips were available; its instruction set was enhanced over the 8008; and its full 16-bit address bus (versus the 14-bit one of the 8008) enabled it to access 64 KB of memory, four times more than the 8008's range of 16 KB. It was used in the
Altair 8800 The Altair 8800 is a microcomputer designed in 1974 by Micro Instrumentation and Telemetry Systems, MITS and based on the Intel 8080 central processing unit, CPU. Interest grew quickly after it was featured on the cover of the January 1975 issue o ...

Altair 8800
and subsequent
S-100 bus The S-100 bus or Altair bus, IEEE 696-1983 ''(withdrawn)'', is an early computer bus In computer architecture In computer engineering, computer architecture is a set of rules and methods that describe the functionality, organization, and ...
personal computers until it was replaced by the
Z80 The Z80 is an 8-bit In computer architecture, 8-bit integer (computer science), integers or other data#Uses of data in computing, data units are those that are 8 bits wide (1 octet). Also, 8-bit central processing unit, CPU and arithmeti ...

Z80
in this role, and was the original target CPU for
CP/M CP/M, originally standing for Control Program/Monitor and later Control Program for Microcomputers, is a mass-market operating system An operating system (OS) is system software System software is software designed to provide a platform f ...
operating systems developed by
Gary Kildall Gary Arlen Kildall (; May 19, 1942 – July 11, 1994) was an American computer scientist A computer scientist is a person who has acquired the knowledge of computer science Computer science deals with the theoretical foundations o ...
. The 8080 directly influenced the later
x86 architecture x86 is a family of instruction set architectures initially developed by Intel based on the Intel 8086 microprocessor and its Intel 8088, 8088 variant. The 8086 was introduced in 1978 as a fully 16-bit extension of Intel's 8-bit Intel 8080, ...
. Intel designed the 8086 to have its
assembly language In computer programming Computer programming is the process of designing and building an executable computer program to accomplish a specific computing result or to perform a particular task. Programming involves tasks such as analysis, genera ...
be similar enough to the 8080, with most instructions mapping directly onto each other, that transpiled 8080 assembly code could be executed on the 8086.


History

Microprocessor customers were reluctant to adopt the 8008 because of limitations such as the single addressing mode, low clock speed, low pin count, and small on-chip stack, which restricted the scale and complexity of software. There were several proposed designs for the 8080, ranging from simply adding stack instructions to the 8008 to a complete departure from all previous Intel architectures. The final design was a compromise between the proposals.
Federico Faggin Federico Faggin (, ; born 1 December 1941) 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 Intel 4004, 4004 (MCS-4) project and ...

Federico Faggin
, the originator of the 8080 architecture in early 1972, proposed the chip to Intel's management and pushed for its implementation. He finally got the permission to develop it six months later. Faggin hired
Masatoshi Shima is a Japanese electronics engineer Image:Silego clock generator.JPG, Printed circuit board Electronic engineering (also called electronics and communications engineering) is an electrical engineering discipline which utilizes nonlinear and acti ...

Masatoshi Shima
, who helped design the 4004 with him, from Japan in November 1972. Shima did the detailed design under Faggin's direction, using the design methodology for random logic with silicon gate that Faggin had created for the 4000 family. The 8080 was explicitly designed to be a general-purpose microprocessor for a larger number of customers. Much of the development effort was spent trying to integrate the functionalities of the 8008's supplemental chips into one package. It was decided early in development that the 8080 was not to be binary-compatible with the 8008, instead opting for source compatibility once run through a transpiler, to allow new software to not be subject to the same restrictions as the 8008. For the same reason, as well as the expand the capabilities of stack-based routines and interrupts, the stack was moved to external memory. Noting the specialized use of general-purpose registers by programmers in mainframe systems, Stanley Mazor, the chip architect, decided the 8080's registers would be specialized, with register pairs having a different set of uses. This also allowed the engineers to more effectively use transistors for other purposes. Shima finished the layout in August 1973. After the regulation of NMOS fabrication, a prototype of the 8080 was completed in January 1974. It had a flaw, in that driving with standard TTL devices increased the ground voltage because high current flowed into the narrow line. Intel had already produced 40,000 units of the 8080 at the direction of the sales section before Shima characterized the prototype. It was released as requiring Low-power Schottky TTL (LS TTL) devices. The 8080A fixed this flaw. Intel offered an
instruction set simulator An instruction set simulator (ISS) is a simulation A simulation is the imitation of the operation of a real-world process or system over time. Simulations require the use of Conceptual model , models; the model represents the key characteristi ...
for the 8080 named INTERP/80 to run compiled
PL/M The PL/M programming language (an acronym of ''Programming Language for Microcomputers'') is a high-level programming language, language conceived and developed by Gary Kildall in 1973 for Hank Smith (Intel), Hank Smith at Intel for its list of I ...
programs. It was written by
Gary Kildall Gary Arlen Kildall (; May 19, 1942 – July 11, 1994) was an American computer scientist A computer scientist is a person who has acquired the knowledge of computer science Computer science deals with the theoretical foundations o ...
while he worked as a consultant for Intel.


Description


Programming model

The Intel 8080 is the successor to the
8008
8008
. It uses the same basic
instruction set In computer science Computer science deals with the theoretical foundations of information, algorithms and the architectures of its computation as well as practical techniques for their application. Computer science is the study of co ...
and
register A register is an authoritative list of one kind of information. Register or registration may refer to: Arts entertainment, and media Music * Register (music), the relative "height" or range of a note, melody, part, instrument, etc. * ''Regis ...
model as the 8008, although it is neither source code compatible nor binary code compatible with its predecessor. Every instruction in the 8008 has an equivalent instruction in the 8080. The 8080 also adds 16-bit operations in its instruction set. Whereas the 8008 required the use of the HL register pair to indirectly access its 14-bit memory space, the 8080 added addressing modes to allow direct access to its full 16-bit memory space. The internal 7-level push-down
call stack In computer science Computer science deals with the theoretical foundations of information, algorithms and the architectures of its computation as well as practical techniques for their application. Computer science is the study of Algor ...
of the 8008 was replaced by a dedicated 16-bit stack-pointer (SP) register. The 8080's 40-pin DIP packaging permits it to provide a 16-bit
address bus In computer architecture In computer engineering Computer engineering (CoE or CpE) is a branch of engineering Engineering is the use of scientific method, scientific principles to design and build machines, structures, and other ...
and an 8-bit
data bus In computer architecture In computer engineering, computer architecture is a set of rules and methods that describe the functionality, organization, and implementation of computer A computer is a machine that can be programmed to carry ...
, enabling access to 64 
KiB The byte is a unit of digital information that most commonly consists of eight bit The bit is a basic unit of information in computing Computing is any goal-oriented activity requiring, benefiting from, or creating computing machinery. It ...
(216 bytes) of memory.


Registers

The processor has seven 8-bit registers (A, B, C, D, E, H, and L), where A is the primary 8-bit accumulator. The other six registers can be used as either individual 8-bit registers or in three 16-bit register pairs (BC, DE, and HL, referred to as B, D and H in Intel documents) depending on the particular instruction. Some instructions also enable the HL register pair to be used as a (limited) 16-bit accumulator. A pseudo-register M, which refers to the dereferenced memory location pointed to by HL, can be used almost anywhere other registers can be used. The 8080 has a 16-bit
stack pointer In computer science Computer science deals with the theoretical foundations of information, algorithms and the architectures of its computation as well as practical techniques for their application. Computer science is the study of Algor ...
to memory, replacing the 8008's internal
stack
stack
, and a 16-bit
program counter The program counter (PC), commonly called the instruction pointer (IP) in Intel Intel Corporation is an American multinational corporation A multinational company (MNC) is a corporate A corporation is an organization—usually a gr ...
.


Flags

The processor maintains internal flag bits (a
status register A status register, flag register, or condition code register (CCR) is a collection of status flag A flag is a piece of textile, fabric (most often rectangular or quadrilateral) with a distinctive design and colours. It is used as a symbol, a si ...
), which indicate the results of arithmetic and logical instructions. Only certain instructions affect the flags. The flags are: *
Sign A sign is an object Object may refer to: General meanings * Object (philosophy), a thing, being, or concept ** Entity, something that is tangible and within the grasp of the senses ** Object (abstract), an object which does not exist at ...
(S), set if the result is negative. *
Zero 0 (zero) is a number A number is a mathematical object A mathematical object is an abstract concept arising in mathematics. In the usual language of mathematics, an ''object'' is anything that has been (or could be) formally defined, and ...
(Z), set if the result is zero. * Parity (P), set if the number of 1 bits in the result is even. * Carry (C), set if the last addition operation resulted in a carry or if the last subtraction operation required a borrow * Auxiliary carry (AC or H), used for
binary-coded decimal In computing and electronics, electronic systems, binary-coded decimal (BCD) is a class of Binary numeral system, binary encodings of decimal numbers where each numerical digit, digit is represented by a fixed number of bits, usually four or ei ...
arithmetic (BCD). The carry bit can be set or complemented by specific instructions. Conditional-branch instructions test the various flag status bits. The flags can be copied as a group to the accumulator. The A accumulator and the flags together are called the PSW register, or program status word.


Commands, instructions

As with many other 8-bit processors, all instructions are encoded in one byte (including register numbers, but excluding immediate data), for simplicity. Some can be followed by one or two bytes of data, which can be an immediate operand, a memory address, or a port number. Like more advanced processors, it has automatic CALL and RET instructions for multi-level procedure calls and returns (which can even be conditionally executed, like jumps) and instructions to save and restore any 16-bit register pair on the machine stack. Eight one-byte call instructions () for subroutines exist at the fixed addresses 00h, 08h, 10h, ..., 38h. These are intended to be supplied by external hardware in order to invoke a corresponding
interrupt service routine In computer systems programming, an interrupt handler, also known as an interrupt service routine or ISR, is a special block of code associated with a specific interrupt In digital computers, an interrupt is a response by the central processi ...
, but are also often employed as fast
system call In computing Computing is any goal-oriented activity requiring, benefiting from, or creating computing machinery. It includes the study and experimentation of algorithmic processes and development of both computer hardware , hardware and so ...
s. The instruction that executes slowest is , which is used for exchanging the register pair HL with the value stored at the address indicated by the stack pointer.


=8-bit instructions

= All 8-bit operations with two operands can only be performed on the 8-bit accumulator (the A register). The other operand can be either an immediate value, another 8-bit register, or a memory byte addressed by the 16-bit register pair HL. Increments and decrements can be performed on any 8 bit register or an HL-addressed memory byte. Direct copying is supported between any two 8-bit registers and between any 8-bit register and an HL-addressed memory byte. Due to the regular encoding of the instruction (using a quarter of available opcode space), there are redundant codes to copy a register into itself (, for instance), which are of little use, except for delays. However, the systematic opcode for is instead used to encode the halt ( ) instruction, halting execution until an external reset or interrupt occurs.


=16-bit operations

= Although the 8080 is generally an 8-bit processor, it has limited abilities to perform 16-bit operations. Any of the three 16-bit register pairs (BC, DE, or HL, referred to as B, D, H in Intel documents) or SP can be loaded with an immediate 16-bit value (using ), incremented or decremented (using and ), or added to HL (using ). By adding HL to itself, it is possible to achieve the same result as a 16-bit arithmetical left shift with one instruction. The only 16-bit instructions that affect any flag is , which sets the CY (carry) flag in order to allow for programmed 24-bit or 32-bit
arithmetic Arithmetic (from the Ancient Greek, Greek wikt:en:ἀριθμός#Ancient Greek, ἀριθμός ''arithmos'', 'number' and wikt:en:τική#Ancient Greek, τική wikt:en:τέχνη#Ancient Greek, έχνη ''tiké échne', 'art' or 'cr ...
(or larger), needed to implement
floating-point arithmetic In computing Computing is any goal-oriented activity requiring, benefiting from, or creating computing machinery. It includes the study and experimentation of algorithmic processes and development of both computer hardware , hardware and soft ...
. A stack frame can be allocated using and . A branch to a computed pointer can be executed with . loads HL from directly addressed memory and stores HL likewise. The instruction exchanges the values of the HL and DE register pairs. exchanges last item pushed on stack with HL.


Input/output scheme


Input output port space

The 8080 supports up to 256
input/output In computing, input/output (I/O, or informally io or IO) is the communication between an information processing system, such as a computer, and the outside world, possibly a human or another information processing system. Information, Inputs are ...
(I/O) ports, accessed via dedicated I/O instructions taking port addresses as operands. This I/O mapping scheme is regarded as an advantage, as it frees up the processor's limited address space. Many CPU architectures instead use so-called
memory-mapped I/O Memory-mapped I/O (MMIO) and port-mapped I/O (PMIO) are two complementary methods of performing input/output In computing, input/output (I/O, or informally io or IO) is the communication between an information processing system, such as a compu ...
(MMIO), in which a common address space is used for both RAM and peripheral chips. This removes the need for dedicated I/O instructions, although a drawback in such designs may be that special hardware must be used to insert wait states, as peripherals are often slower than memory. However, in some simple 8080 computers, I/O is indeed addressed as if they were memory cells, "memory-mapped", leaving the I/O commands unused. I/O addressing can also sometimes employ the fact that the processor outputs the same 8-bit port address to both the lower and the higher address byte (i.e., would put the address 0505h on the 16-bit address bus). Similar I/O-port schemes are used in the backward-compatible Zilog Z80 and Intel 8085, and the closely related x86 microprocessor families.


Separate stack space

One of the bits in the processor state word (see below) indicates that the processor is accessing data from the stack. Using this signal, it is possible to implement a separate stack memory space. This feature is seldom used.


The internal state word

For more advanced systems, during one phase of its working loop, the processor set its "internal state byte" on the data bus. This byte contains flags that determine whether the memory or I/O port is accessed and whether it is necessary to handle an interrupt. The interrupt system state (enabled or disabled) is also output on a separate pin. For simple systems, where the interrupts are not used, it is possible to find cases where this pin is used as an additional single-bit output port (the popular
Radio-86RK The Radio-86RK (russian: Радио-86РК) is a build-it-yourself home computer designed in the Soviet Union The Soviet Union,. officially the Union of Soviet Socialist Republics. (USSR),. was a that spanned during its existence from 19 ...
computer made in the
Soviet Union The Soviet Union,. officially the Union of Soviet Socialist Republics. (USSR),. was a that spanned during its existence from 1922 to 1991. It was nominally a of multiple national ; in practice and were highly until its final years. The ...
, for instance).


Example code

The following 8080/8085
assembler Assembler may refer to: Arts and media * Nobukazu Takemura Nobukazu Takemura (竹村延和 ''Takemura Nobukazu'') is a Japanese musician and artist. Born in Hirakata, Osaka in August 1968, he became interested in music at a young age by listenin ...
source code is for a subroutine named that copies a block of data bytes of a given size from one location to another. The data block is copied one byte at a time, and the data movement and looping logic utilizes 16-bit operations.


Pin use

The address bus has its own 16 pins, and the data bus has 8 pins that are usable without any multiplexing. Using the two additional pins (read and write signals), it is possible to assemble simple microprocessor devices very easily. Only the separate IO space, interrupts, and DMA need added chips to decode the processor pin signals. However, the pin load capacity is limited; even simple computers often require bus amplifiers. The processor needs three power sources (−5, +5, and +12 V) and two non-overlapping high-amplitude synchronizing signals. However, at least the late Soviet version КР580ВМ80А was able to work with a single +5 V power source, the +12 V pin being connected to +5 V and the −5 V pin to ground. The pin-out table, from the chip's accompanying documentation, describes the pins as follows:


Support chips

A key factor in the success of the 8080 was the broad range of support chips available, providing serial communications, counter/timing, input/output, direct memory access, and programmable interrupt control amongst other functions:
8238
– System controller and bus driver * 8251 – Communication controller * 8253
Programmable interval timer#REDIRECT Programmable interval timerIn computing Computing is any goal-oriented activity requiring, benefiting from, or creating computing machinery. It includes the study and experimentation of algorithmic processes and development of both comput ...
* 8255 – Programmable peripheral interface * 8257 – DMA controller *
8259 The Intel Intel Corporation is an American multinational corporation and technology company headquartered in Santa Clara, California, Santa Clara, California, in Silicon Valley. It is the world's largest semiconductor chip manufacturer by ...

8259
Programmable interrupt controller In computing Computing is any goal-oriented activity requiring, benefiting from, or creating computing machinery. It includes the study and experimentation of algorithmic processes and development of both computer hardware , hardware and soft ...


Physical implementation

The 8080
integrated circuit An integrated circuit or monolithic integrated circuit (also referred to as an IC, a chip, or a microchip) is a set of electronic circuit 200px, A circuit built on a printed circuit board (PCB). An electronic circuit is composed of indiv ...

integrated circuit
uses non-saturated enhancement-load nMOS gates, demanding extra voltages (for the load-gate bias). It was manufactured in a
silicon gateIn electronics, a self-aligned gate is a transistor manufacturing feature whereby a refractory gate (transistor), gate electrode region of a MOSFET (metal–oxide–semiconductor field-effect transistor) is used as a mask for the doping of the sourc ...
process using a minimal feature size of 6 µm. A single layer of metal is used to
interconnect In telecommunications, interconnection is the physical linking of a common carrier, carrier's telecommunications network, network with equipment or facilities not belonging to that network. The term may refer to a connection between a carrier's ...
the approximately 4,500 transistors in the design, but the higher
resistance Resistance may refer to: Arts, entertainment, and media Comics * Either of two similarly named but otherwise unrelated comic book series, both published by Wildstorm: ** ''Resistance'' (comics), based on the video game of the same title ** ''Th ...
polysilicon Polycrystalline silicon, or multicrystalline silicon, also called polysilicon or poly-Si, is a high purity, polycrystalline A crystallite is a small or even microscopic crystal A crystal or crystalline solid is a solid material whose const ...

polysilicon
layer, which required higher voltage for some interconnects, is implemented with transistor gates. The
die Die, as a verb, refers to death, the cessation of life. Die may also refer to: Games * Die, singular of dice, small throwable objects used for producing random numbers Manufacturing * Die (integrated circuit), a rectangular piece of a semiconduct ...
size is approximately 20 mm2.


The industrial impact


Applications and successors

The 8080 is used in many early microcomputers, such as the MITS
Altair 8800 The Altair 8800 is a microcomputer designed in 1974 by Micro Instrumentation and Telemetry Systems, MITS and based on the Intel 8080 central processing unit, CPU. Interest grew quickly after it was featured on the cover of the January 1975 issue o ...

Altair 8800
Computer,
Processor Technology Processor Technology Corporation was a personal computer company founded in April 1975 by Gary Ingram and Bob Marsh in Berkeley, California Berkeley ( ) is a city on the eastern shore of San Francisco Bay in northern Alameda County, California, ...
SOL-20 The Sol-20 was the first fully assembled microcomputer A microcomputer is a small, relatively inexpensive computer with a microprocessor as its central processing unit (CPU). It includes a microprocessor, Computer memory, memory and minimal in ...

SOL-20
Terminal Computer and
IMSAI 8080 The IMSAI 8080 was an early microcomputer A microcomputer is a small, relatively inexpensive computer A computer is a machine that can be programmed to carry out sequences of arithmetic or logical operations automatically. Modern compu ...
Microcomputer, forming the basis for machines running the
CP/M CP/M, originally standing for Control Program/Monitor and later Control Program for Microcomputers, is a mass-market operating system An operating system (OS) is system software System software is software designed to provide a platform f ...
operating system (the later, almost fully compatible and more able,
Zilog Z80 The Z80 is an 8-bit In computer architecture In computer engineering, computer architecture is a set of rules and methods that describe the functionality, organization, and implementation of computer systems. Some definitions of archite ...

Zilog Z80
processor would capitalize on this, with Z80 & CP/M becoming the dominant CPU and OS combination of the period circa 1976 to 1983 much as did the
x86 x86 is a family of instruction set architecture In computer science, an instruction set architecture (ISA), also called computer architecture, is an abstract model of a computer. A device that executes instructions described by that ISA, ...

x86
&
DOS DOS (, ) is a platform-independent acronym for disk operating system which later became a common shorthand for disk-based operating systems on IBM PC compatible IBM PC compatible computers are similar to the original IBM Personal Computer, IB ...

DOS
for the PC a decade later). In 1979, even after the introduction of the Z80 and 8085 processors, five manufacturers of the 8080 were selling an estimated 500,000 units per month at a price around $3 to $4 each. The first single-board microcomputers, such as
MYCRO-1 The MYCRO-1 was a microcomputer manufactured and sold by Mycron of Oslo, Norway. Built around the Intel 8080 central processing unit, CPU, it was one of the first commercial single-board computer after the Intel System Development Kit#Intel SDK-80, ...

MYCRO-1
and the ''dyna-micro'' / MMD-1 (see:
Single-board computer A single-board computer (SBC) is a complete computer A computer is a machine that can be programmed to carry out sequences of arithmetic or logical operations automatically. Modern computers can perform generic sets of operations known as ...
) were based on the Intel 8080. One of the early uses of the 8080 was made in the late 1970s by Cubic-Western Data of San Diego, CA in its Automated Fare Collection Systems custom designed for mass transit systems around the world. An early industrial use of the 8080 is as the "brain" of the DatagraphiX Auto-COM (Computer Output Microfiche) line of products which takes large amounts of user data from reel-to-reel tape and images it onto microfiche. The Auto-COM instruments also include an entire automated film cutting, processing, washing, and drying sub-system. Several early video
arcade game An arcade game or coin-op game is a coin-operated entertainment machine typically installed in public businesses such as restaurants, bars and amusement arcades. Most arcade games are presented as primarily game of skill, games of skill and in ...

arcade game
s were built around the 8080 microprocessor, including ''
Space Invaders is a 1978 shoot 'em up Shoot 'em up (also known as shmup or STG Davies, Jonti. ''. GameSpy GameSpy was an American provider of online multiplayer and Matchmaking (video games), matchmaking middleware for video games founded in 1996 by ...

Space Invaders
'', one of the most popular arcade games ever made.
Zilog Zilog, Inc. is an American manufacturer of 8-bit In computer architecture, 8-bit integer (computer science), integers or other data#Uses of data in computing, data units are those that are 8 bits wide (1 octet). Also, 8-bit central proces ...
introduced the
Z80 The Z80 is an 8-bit In computer architecture, 8-bit integer (computer science), integers or other data#Uses of data in computing, data units are those that are 8 bits wide (1 octet). Also, 8-bit central processing unit, CPU and arithmeti ...

Z80
, which has a compatible
machine language In computer programming Computer programming is the process of designing and building an executable computer program to accomplish a specific computing result or to perform a particular task. Programming involves tasks such as analysis, ...
instruction set and initially used the same assembly language as the 8080, but for legal reasons, Zilog developed a syntactically-different (but code compatible) alternative assembly language for the Z80. At Intel, the 8080 was followed by the compatible and electrically more elegant 8085. Later, Intel issued the assembly-language compatible (but not binary-compatible) 16-bit
8086 The 8086 (also called iAPX 86) is a 16-bit 16-bit microcomputer A microcomputer is a small, relatively inexpensive computer A computer is a machine that can be programmed to carry out sequences of arithmetic or logical operations aut ...
and then the 8/16-bit
8088 The Intel 8088 ("''eighty-eighty-eight''", also called iAPX 88) microprocessor A microprocessor is a computer processor where the data processing logic and control is included on a single integrated circuit An integrated circuit or ...
, which was selected by
IBM International Business Machines Corporation (IBM) is an American multinational technology company headquartered in Armonk, New York, with operations in over 170 countries. The company began in 1911, founded in Endicott, New York, as the C ...

IBM
for its new
PC
PC
to be launched in 1981. Later
NEC is a Japanese multinational information technology and electronics Electronics comprises the physics, engineering, technology and applications that deal with the emission, flow and control of electrons in vacuum and matter. It uses active d ...
made the
NEC V20 The NEC V20 was a microprocessor A microprocessor is a computer processor where the data processing logic and control is included on a single integrated circuit, or a small number of integrated circuits. The microprocessor contains the arit ...
(an 8088 clone with
Intel 80186 The Intel 80186, also known as the iAPX 186, or just 186, is a microprocessor A microprocessor is a computer processor where the data processing logic and control is included on a single integrated circuit An integrated circuit ...
instruction set compatibility) which also supports an 8080 emulation mode. This is also supported by NEC's V30 (a similarly enhanced 8086 clone). Thus, the 8080, via its
instruction set architecture In computer science Computer science deals with the theoretical foundations of information, algorithms and the architectures of its computation as well as practical techniques for their application. Computer science is the study of , ...
(ISA), made a lasting impact on computer history. A number of processors compatible with the Intel 8080A were manufactured in the
Eastern Bloc The Eastern Bloc, also known as the Communist Bloc, the Socialist Bloc and the Soviet Bloc, was the group of socialist state A socialist state, socialist republic, or socialist country, sometimes referred to as a workers' state or workers' ...
: the
KR580VM80A The KR580VM80A (russian: КР580ВМ80А) is a Soviet microprocessor A microprocessor is a computer processor where the data processing logic and control is included on a single integrated circuit An integrated circuit or monolithic ...
(initially marked as KP580ИK80) in the
Soviet Union The Soviet Union,. officially the Union of Soviet Socialist Republics. (USSR),. was a that spanned during its existence from 1922 to 1991. It was nominally a of multiple national ; in practice and were highly until its final years. The ...
, the MCY7880 made by Unitra CEMI in
Poland Poland, officially the Republic of Poland, is a country located in Central Europe. It is divided into 16 Voivodeships of Poland, administrative provinces, covering an area of , and has a largely Temperate climate, temperate seasonal cli ...

Poland
, the MHB8080ASoviet chips and their western analogs
CPU-world. Retrieved on October 23, 2011.
made by TESLA in
Czechoslovakia , , yi, טשעכאסלאוואקיי, , common_name = Czechoslovakia , life_span = 1918–19391945–1992 , p1 = Austria-Hungary , image_p1 = , s1 = Czech Re ...

Czechoslovakia
, the 8080APC made by
Tungsram Tungsram located in Hungary Hungary ( hu, Magyarország ) is a country in Central Europe. It borders Slovakia to the north, Ukraine to the northeast, Romania to the east and southeast, Serbia to the south, Croatia and Slovenia to the southw ...

Tungsram
/ MEV in
Hungary Hungary ( hu, Magyarország ) is a in . Spanning of the , it is bordered by to the north, to the northeast, to the east and southeast, to the south, and to the southwest and to the west. Hungary has a population of 10 million, mostl ...

Hungary
, and the MMN8080 made by Microelectronica Bucharest in Romania. , the 8080 is still in production at Lansdale Semiconductors. File:AMD C8080A.jpg, AMD Am9080 File:Poland MCY7880 1.jpg, CEMI MCY7880 (Poland) File:580IK80.jpg, Kvazar Kiev KR580VM80A, K580IK80 (Soviet Union) File:Mitsubishi M5L8080AP 1.jpg, Mitsubishi Electric M5L8080 File:NatSem INS8080AJ 1.jpg, National Semiconductor INS8080 File:NEC 8080AF 1.jpg, NEC μPD8080AF File:OKI MSM8080A 1.jpg, Oki Electric Industry, OKI MSM8080 File:Siemens SAB8080A 1.jpg, Siemens SAB8080 File:Signetics MP8080AI 1.jpg, Signetics MP8080 File:KL Tesla MHB8080.jpg, Tesla (Czechoslovak company) MHB8080 File:TI TMS8080JL 1.jpg, Texas Instruments TMS8080


Industry change

The 8080 also changed how computers were created. When the 8080 was introduced, computer systems were usually created by computer manufacturers such as Digital Equipment Corporation, Hewlett Packard, or
IBM International Business Machines Corporation (IBM) is an American multinational technology company headquartered in Armonk, New York, with operations in over 170 countries. The company began in 1911, founded in Endicott, New York, as the C ...

IBM
. A manufacturer would produce the whole computer, including processor, terminals, and system software such as compilers and operating system. The 8080 was designed for almost any application ''except'' a complete computer system. Hewlett Packard developed the HP 2640 series of smart terminals around the 8080. The HP 2647 is a terminal which runs the programming language BASIC on the 8080. Microsoft's founding product, Microsoft BASIC, was originally programmed for the 8080. The 8080 and 8085 gave rise to the 8086, which was designed as a source code compatible, albeit not Binary-code compatibility, binary compatible, extension of the 8080. This design, in turn, later spawned the
x86 x86 is a family of instruction set architecture In computer science, an instruction set architecture (ISA), also called computer architecture, is an abstract model of a computer. A device that executes instructions described by that ISA, ...

x86
family of chips, which continue to be Intel's primary line of processors. Many of the 8080's core machine instructions and concepts survive in the widespread x86 platform. Examples include the registers named ''A'', ''B'', ''C'', and ''D'' and many of the flags used to control conditional jumps. 8080 assembly code can still be directly translated into x86 instructions, for all of its core elements are still present.


Cultural impact

* Asteroid 8080 Intel is named as a pun and praise on the name of Intel 8080. * Microsoft's published phone number, 425-882-8080, was chosen because much early work was on this chip. * Many of Intel's main phone numbers also take a similar form: xxx-xxx-8080


See also

*
CP/M CP/M, originally standing for Control Program/Monitor and later Control Program for Microcomputers, is a mass-market operating system An operating system (OS) is system software System software is software designed to provide a platform f ...
– operating system *
S-100 bus The S-100 bus or Altair bus, IEEE 696-1983 ''(withdrawn)'', is an early computer bus In computer architecture In computer engineering, computer architecture is a set of rules and methods that describe the functionality, organization, and ...
* MPT8080


References


Further reading

* ; 495 pages * ; 332 pages * ; 466 pages * ; 180 pages


External links


Intel and other manufacturers' 8080 CPU images and descriptions at cpu-collection.de

Scan of the Intel 8080 data book at DataSheetArchive.com



8080 Emulator written in JavaScript

Intel 8080/KR580VM80A emulator in JavaScript

Intel 8080 Microcomputer Systems User's Manual (September 1975, 262 pages)

Intel 8080 Microcomputer Systems User's Manual (September 1975, 234 pages)

Intel 8080/8085 Instruction Reference Card
* {{Authority control Computer-related introductions in 1974 8-bit microprocessors