INTRODUCTION TO MCS-85™

purpose organization and instruction set matched the requirements of these products. Recognizing that hardware was but a small part in the overall system picture, Intel developed both hardware and software tools for the design engineer so that the transition from pro- totype to production would be as simple and fast as possible. The commitment of providing a total systems approach with the 8008 micro- computer system was actually the basis for the sophisticated, comprehensive development tools that Intel has available today.

THE 8080A MICROPROCESSOR

With the advent of high-production N-channel RAM memories and 40 pin DIP packaging, Intel designed the 8080A microprocessor. It was designed to be software compatible with the 8008 so that the existing users of the 8008 could preserve their investment in software and at the same time provide dramatically increased per- formance (2 micro-second instruction execu- tion), while reducing the amount of components necessary to implement a system. Additions were made to the basic instruction set to take advantage of this increased performance and large system-type features were included on- chip such as DMA, 16-bit addressing and exter- nal stack memory so that the total spectrum of application could be significantly increased. The 8080 was first sampled in December 1973. Since that time it has become the standard of the industry and is accepted as the primary building block for more microcomputer based applications than all other microcomputer sys- tems combined.

A TOTAL SYSTEMS COMMITMENT

The Intel® 8080A Microcomputer System en- compasses a total systems commitment to the user to fully support his needs both in develop- ing prototype systems and reliable, high volume production. From complex MOS/LSI peripheral components to resident high level systems language (PUM) the Intel® 8080 Microcom- puter System provides the most comprehen- sive, effective solution to today'ssystem pro- blems.

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Intel MCS-80/85 manual Introduction to MCS-85
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MCS-80/85 specifications

The Intel MCS-80/85 family, introduced in the late 1970s, is a seminal collection of microprocessors that played a pivotal role in the early days of computing. The MCS-80 series, initially targeting embedded systems and control applications, gained remarkable attention due to its innovative architecture and flexible programming capabilities.

The MCS-80 family is anchored by the 8080 microprocessor, which was one of the first fully integrated 8-bit microprocessors. Released in 1974, the 8080 operated at clock speeds ranging from 2 MHz to 3 MHz and featured a 16-bit address bus capable of addressing up to 64KB of memory. The processor’s instruction set included around 78 instructions, providing extensive capabilities for data manipulation, logic operations, and branching.

Complementing the 8080 was a suite of support chips, forming the MCS-80 platform. The most notable among them was the 8155, which integrated a static RAM, I/O ports, and a timer, tailored for ease of designing systems around the 8080. Other support chips included the 8085, which provided improvements with an integrated clock generator, making it compatible with more modern designs and applications.

The MCS-85 series, on the other hand, revolves around the 8085 microprocessor, which provided a more advanced architecture. The 8085 operated at clock speeds of up to 6 MHz and came with a 16-bit address bus, similar to its predecessor. However, it introduced more sophisticated features, including an enhanced instruction set and support for interrupt-driven programming. These enhancements made the 8085 especially appealing to developers working in real-time processing environments.

The MCS-80/85 family utilized NMOS technology, known for its lower power consumption and higher performance compared to previous technologies like TTL. The family’s architecture allowed for easy interfacing with a variety of peripherals, making it a favorite for educational institutions and hobbyists embarking on computer engineering projects.

With its robustness, versatility, and affordability, the Intel MCS-80/85 microprocessors laid the groundwork for many subsequent microcomputer systems and applications. The legacy of this powerful family continues to influence modern microprocessor design, emphasizing the importance of reliable architecture in a rapidly evolving technology landscape.
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