Understanding the Naming of the 8085 Microprocessor

Microprocessors are named according to the length of their data bus, which determines the amount of data they can process at once. For example, a 4-bit processor, an 8-bit processor, a 16-bit processor, and so on. The 8085 microprocessor, with its 8-bit data bus, is a perfect example of this naming convention. It processes 8 bits of data at a time, making it an 8-bit processor. However, it is important to differentiate between the data bus and the address bus, which controls how much memory the processor can access directly.

Why is it called 8085?

The naming of the 8085 microprocessor is a blend of technical specifications and historical context. Here is the breakdown of its name:

First “80” represents the decade in which it was developed: Third “8” signifies that it is an 8-bit processor: Fourth “5” denotes its operating voltage of 5 volts.

Historical Context and Evolution of Microprocessors

Microprocessors have a fascinating history that traces back to simple tools like the abacus, through complex mechanisms like weaving machines and punchcards, and eventually to the revolutionary microprocessors of today. Here's a brief overview of this evolution:

Abacus: The abacus is a binary calculator where beads on a rod represent either a '0' or a '1'. Its simplicity belies its power in performing calculations. Mechanical Devices: Early mechanical devices, such as weaving machines, used binary logic to control intricate patterns. Sabotage was even a method to disrupt these systems by throwing wooden shoes into them. Electromechanical Relays and Vacuum Tubes: Rows of electromechanical relays and vacuum tubes were used to perform calculations, the rudimentary version of what modern computers do today. A moth was famously responsible for a relay issue, which led to the invention of the term 'debugging'. Semiconductors: The invention of semiconductors marked a significant advancement. These materials can amplify and negate current quickly, making them ideal for processing information at the speed of electricity. Micro-circuits: By printing a pattern of chemicals onto semiconductors and baking them, circuits could be made smaller, consuming less electricity. The 8085 was printed using patterns that were 3 micrometers wide, setting a precedent for future advancements.

The 8085 Microprocessor

The 8085 is an Intel product, introduced in 1976. It is capable of performing 8-bit mathematical operations but can access data addresses with a 16-bit bus. This means it can store a program with 65,025 units of 8-bit data. It is well-regarded for its ability to perform tasks such as Space Invaders, where numbers from 0 to 255 were used to create music and images on a television screen.

Modern Day 8-Bit Systems

Today, when you buy a personal computer, it contains numerous 'abacusses' called cores. A four-core microprocessor, for instance, contains four of these cores. While the 8085 is a product of the 1970s, its influence can still be felt in the modern tech landscape. It represents a significant milestone in the evolution of microprocessors and computing technology.