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Zilog Z80: the small CPU that powered an entire generation

Before powerful laptops and smartphones, there were small computers that felt magical for their time.

Many of them were powered by one chip:

Zilog Z80

The Z80 is one of the most important CPUs ever made not because it was fast, but because it was everywhere.

What the Z80 actually is

The Zilog Z80 is an 8-bit microprocessor released in the mid-1970s.

It was designed to be:
• simple
• cheap
• flexible
• easy to use

It was compatible with the older Intel 8080, but added many improvements. That made it very attractive to computer makers.

Why the Z80 became so popular

The Z80 succeeded because it solved real problems.

It had:
• more registers than the 8080
• built-in memory refresh support
• simple instruction set
• good performance for low cost

This meant:
• fewer extra chips needed
• cheaper computers
• simpler system design

For small companies and hobbyists, this mattered a lot.

Where the Z80 was used

The Z80 was used in a huge number of early computers and devices.

Famous examples:
• Sinclair ZX Spectrum
• MSX home computers
• TRS-80
• Amstrad CPC
• early arcade machines

If you used a home computer in the 1980s, there is a good chance it had a Z80 inside.

Z80 and operating systems

The Z80 was not meant for modern operating systems.

Instead, it ran:
• simple ROM-based systems
• BASIC interpreters
• CP/M operating system

CP/M was especially important.
Before MS-DOS became popular, CP/M on Z80 systems was very common.

Was the Z80 used in embedded systems?

Yes and this is why it still matters today.

Z80 chips are still used in:
• calculators
• industrial controllers
• test equipment
• communication devices

They are reliable, predictable, and easy to program.

Some Z80-based chips are still manufactured today.

Why the Z80 survived for so long

The Z80 lasted because:
• it was simple
• it was well documented
• engineers trusted it
• existing software kept working

Even when faster CPUs appeared, the Z80 stayed useful in small control systems.

Z80 today

You won’t find a Z80 in:
• modern laptops
• phones
• gaming PCs

But you will still find it in:
• embedded hardware
• education
• retro computers
• hobby projects

Many people still learn assembly language using the Z80 because it is easy to understand.

Why the Z80 still matters

The Z80 helped define:
• early personal computing
• affordable home computers
• how simple CPUs should be designed

*It proved that a small, well-designed processor can change the world.
*

Final thoughts

The Zilog Z80 didn’t try to be powerful.

It tried to be useful.

And for a very long time, it succeeded.

That’s why it’s still remembered and still used today

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