Home > Intel 8080

1 Description

The Intel 8080 was the successor to the Intel 8008 (with which it was assembly language source-compatible because it used the same instruction set developed by Computer Terminal Corporation). The 8080's large 40 pin DIP packaging permitted it to provide a 16-bit address bus and an 8-bit data bus, allowing easy access to 64 kilobytes of memory. It had seven 8-bit registersIn computer architecture, a processor register is a small amount of very fast computer memory used to speed the execution of computer programs by providing quick access to commonly used values—typically, the values being in the midst of a calculation at a (six of which could be combined into three 16-bit registers), a 16-bit stack pointer to memory (replacing the 8008's internal stackA stack is a data structure that works on the principle of Last In First Out (LIFO). This means that the last item put on the stack is the first item that can be taken off, like a physical stack of plates. A stack-based computer system is one that is base), and a 16-bit program counterThe program counter (also called the instruction pointer in some computers) is a register in a computer processor which indicates where the computer is in its instruction sequence. Depending on the details of the particular machine, it holds either the ad.

The 8080 had 256 I/O ports (allowing I/O devices to be connected without the need to allocate memory space – as is required for memory mapped devices – but at the expense of having programmers deal with separate I/O instructions). The first single-board microcomputersingle-board computer is a complete computer built on a single circuit board. The design is always centered around a microprocessor. The first true single-board computer was probably the MYCRO 1, built around the Intel 8080 CPU. Current Context of Single was built on the basis of the 8080.

2 Impact

The 8080 was used in many early computers, such as the MITS Altair 8800The MITS Altair 8800 is a microcomputer design from 1975, based on the Intel 8080A CPU. Sold as a kit through Popular Electronics magazine, the designers intended to sell only a few hundred to hobbyists, and were surprised when they sold over ten times th and IMSAI 8080The IMSAI 8080 microcomputer, manufactured by IMS A ssociates, I nc. later renamed to IMSAI Manufacturing Corp. in 1976, was an early Intel 8080, S-100 bus based computer, compatible with its main competitor, the earlier MITS Altair 8800, by which it was, forming the basis for machines running the CP/M operating system (the later, fully compatible and more capable, Zilog Z80 processor would capitalize on this, with Z80 & CP/M becoming the dominant CPU & OS combination of the period much like x86 & MS-DOS for the PC a decade later). Shortly after the launch of the 8080, the Motorola 6800 competing design was introduced, and after that, the MOS Technology 6502 clone of the 6800.

At Intel, the 8080 was followed by the compatible and electrically more elegant 8085, and later by the assembly language compatible 16-bit 8086 and then the 8/16-bit 8088, which was selected by IBM for its new PC to be launched in 1981. The 8080, via its ISA, thus got a lasting impact on computer history.