# Zilog Z80A

> variant of the Zilog Z80

**Wikidata**: [Q114405361](https://www.wikidata.org/wiki/Q114405361)  
**Source**: https://4ort.xyz/entity/zilog-z80a

## Summary
The Zilog Z80A is a specific variant and product model of the Zilog Z80 8-bit microprocessor. It operates at a base clock frequency of 4 MHz and is classified as a subclass of the original Z80 architecture. This processor has been widely referenced under aliases such as the Z-80A and Z80-A and serves as the blueprint for hardware clones like the MMN80CPU.

## Key Facts
*   **Classification:** The Zilog Z80A is a distinct product model and a subclass of the Zilog Z80 8-bit microprocessor.
*   **Clock Speed:** It has a defined base clock frequency of 4 MHz.
*   **Parent Architecture:** It is a variant of the Zilog Z80, which was originally released (inception) in March 1976.
*   **Aliases:** The entity is also known by the identifiers Z-80A, Z80-A, Z80A, and Z80A CPU.
*   **Clones:** The MMN80CPU is identified as a direct clone of the Zilog Z80A.
*   **Related Hardware:** The Sharp LH0080 is listed as a related class of hardware.

## FAQs
### Q: What exactly is the Zilog Z80A?
A: The Zilog Z80A is a variant of the Zilog Z80 8-bit microprocessor. It is categorized as a specific product model within the broader Z80 family.

### Q: What is the clock frequency of the Zilog Z80A?
A: The Zilog Z80A operates at a base clock frequency of 4 megahertz (MHz).

### Q: Are there clones of the Zilog Z80A?
A: Yes, the MMN80CPU is documented as a clone of the Zilog Z80A. Additionally, the Sharp LH0080 is a related hardware class.

## Why It Matters
The Zilog Z80A represents a specific, high-performance iteration of one of the most successful 8-bit microprocessor architectures in computing history. While the parent Zilog Z80 (introduced in March 1976) established the fundamental 8-bit architecture, the Z80A variant is significant for standardizing a 4 MHz clock frequency. This speed became a critical benchmark for software and hardware compatibility during the early era of personal computing.

The existence of this entity highlights the maturity of the Z80 ecosystem. The fact that specific product models like the Z80A were cloned (such as the MMN80CPU) and classed alongside similar chips (like the Sharp LH0080) demonstrates its role as a de facto standard in the industry. By defining a specific 4 MHz operating speed, the Z80A provided a reliable target for engineers and developers, ensuring interoperability across different hardware implementations. Its status as a subclass of the Z80 ensures it is recognized not just as a generic chip, but as a distinct commercial product model with precise technical specifications.

## Notable For
*   **Standardized Speed:** Distinguished by its specific 4 MHz base clock frequency.
*   **Lineage:** Being a direct variant of the Zilog Z80, a seminal 8-bit microprocessor.
*   **Industry Adoption:** Serving as the reference design for cloned hardware like the MMN80CPU.
*   **Nomenclature:** Being recognized under multiple specific technical aliases including Z-80A and Z80-A.

## Body

### Technical Classification
The Zilog Z80A is formally classified as a "product model" and a "subclass of" the Zilog Z80. It retains the fundamental 8-bit architecture of its parent processor but is distinguished by its specific operational parameters. It is distinct from the general Z80 family entry, which has a significantly higher volume of documentation (41 sitelinks compared to the Z80A's 1), suggesting the Z80A is a specialized or specific commercial SKU within the broader family.

### Specifications
The primary technical specification defining the Zilog Z80A is its clock frequency. The processor is rated with a base clock frequency of **4 megahertz (MHz)**. This metric is essential for determining the execution speed of instructions and the synchronization of connected hardware components.

### Related Hardware and Clones
The Z80A architecture was licensed or reverse-engineered by other manufacturers, leading to the creation of related hardware classes and direct clones.
*   **Sharp LH0080:** This is listed as a related class of hardware, functioning similarly to the Z80A.
*   **MMN80CPU:** This processor is explicitly defined as a clone of the Zilog Z80A, indicating hardware and functional compatibility with the Zilog design.

### Identification
The entity is represented in knowledge bases by several aliases, reflecting variations in manufacturing labels and common shorthand. These aliases include:
*   Z-80A
*   Z80-A
*   Z80A CPU