# USB-to-PS/2 adapter

> adapter to connect a USB-A mouse/keyboard to a PS/2 port

**Wikidata**: [Q135916526](https://www.wikidata.org/wiki/Q135916526)  
**Source**: https://4ort.xyz/entity/usb-to-ps-2-adapter

## Summary
A USB-to-PS/2 adapter is a hardware device that enables USB-A mice or keyboards to connect to a PS/2 port, bridging newer USB peripherals with older PS/2-compatible systems. It converts USB signals to PS/2 protocol, allowing compatibility between devices with different interfaces. This adapter is distinct from its counterpart, the PS/2-to-USB adapter, based on connector gender and signal direction.

## Key Facts
- Converts USB-A signals to PS/2 protocol for mice/keyboards.
- Uses a USB Standard-A receptacle and a PS/2 connector.
- Opposite of a PS/2-to-USB adapter (distinguished by connector gender).
- Aliases include "USB-PS/2 adapter" and "PS/2 adapter."
- Subclass of the broader USB-PS/2 adapter category.
- Does not require external power for basic functionality.
- Enables legacy PS/2 systems to support USB input devices.

## FAQs
### Q: What does a USB-to-PS/2 adapter do?
A: It allows USB-A mice or keyboards to connect to a PS/2 port, enabling compatibility between modern USB devices and older systems with PS/2 ports.

### Q: How is it different from a PS/2-to-USB adapter?
A: A USB-to-PS/2 adapter connects USB devices to PS/2 ports, while a PS/2-to-USB adapter does the reverse. They are opposites based on connector gender and signal direction.

### Q: Do I need drivers for a USB-to-PS/2 adapter?
A: Most adapters are plug-and-play and do not require additional drivers, though compatibility may vary with specific hardware.

## Why It Matters
The USB-to-PS/2 adapter plays a critical role in maintaining compatibility between generations of computer hardware. As USB replaced PS/2 as the dominant interface for peripherals, these adapters allowed users to continue using newer USB mice and keyboards with legacy systems that only featured PS/2 ports. This bridging technology eased the transition between eras of computing, reducing electronic waste and extending the lifespan of older equipment. It remains relevant in niche scenarios, such as industrial or embedded systems that still rely on PS/2 connectivity, ensuring functional continuity without requiring hardware overhauls.

## Notable For
- Unidirectional conversion of USB signals to PS/2 protocol.
- Physical integration of USB-A and PS/2 connectors in a single device.
- Critical role in legacy system support during the USB/PS/2 transition period.
- Passive design (no external power required for basic operation).

## Body
### Technical Specifications
- **Connectors**: USB Standard-A receptacle (female) and PS/2 connector (male).
- **Functionality**: Converts USB HID (Human Interface Device) signals to PS/2-compatible protocols.
- **Compatibility**: Supports USB 1.1/2.0 mice and keyboards; may not work with USB 3.0+ devices due to protocol differences.

### Functional Role
- **Legacy Support**: Allows modern USB peripherals to function on older systems (e.g., late-1990s to early-2000s PCs) that lack USB ports.
- **Interface Transition**: Facilitated the gradual adoption of USB by providing a cost-effective alternative to replacing entire systems.
- **Design Limitations**: Typically supports only one device at a time (mouse or keyboard), unlike USB hubs.

### Historical Context
- **Relevance Peak**: Most widely used during the early 2000s as USB began superseding PS/2.
- **Decline**: Became less common after 2010 as USB ports became ubiquitous and PS/2 was phased out of mainstream hardware.