What is Berg (Floppy) Connector?
A Berg (Floppy) Connector is a 4-pin power connector once commonly used to supply electricity to 3.5-inch floppy disk drives inside desktop computers. It delivers +5V and +12V DC power from the power supply unit (PSU) and is much smaller than a standard Molex connector, making it suitable for compact legacy storage devices.
Key Takeaways
- A 4-pin power connector designed primarily for floppy disk drives.
- Provides +5V and +12V DC power from the PSU.
- Smaller than the standard 4-pin Molex peripheral connector.
- Rarely included on modern power supplies because floppy drives are obsolete.
- May still be found in legacy PCs, industrial systems, and retro computing projects.
How Did the Berg (Floppy) Connector Evolve?
The Berg connector became popular during the 1980s and 1990s when floppy disk drives were standard components in desktop computers. Named after Berg Electronics, the connector was widely adopted by PC manufacturers.
As floppy drives disappeared in favor of USB flash drives, optical media, SSDs, and cloud storage, motherboard and PSU manufacturers gradually removed native Berg connectors. Today, they mainly survive on legacy hardware and through Molex-to-Berg adapter cables.
Why Does the Berg (Floppy) Connector Exist?
Floppy drives required a compact connector because there was limited space inside the drive chassis. The larger Molex connector used for hard drives and optical drives was physically too large for many floppy drive designs.
The Berg connector solved this problem by providing the required voltages in a much smaller form factor.
How Does the Berg (Floppy) Connector Work?
The connector plugs directly from the power supply into a compatible floppy disk drive.
Its four pins carry:
- +5V DC power
- +12V DC power
- Two ground connections
The keyed connector prevents incorrect insertion by matching the drive's socket orientation.
Key Characteristics
- 4-pin power connector
- Compact rectangular design
- Keyed to reduce incorrect installation
- Provides regulated DC power
- Internal PC power connector
- Used only for power, not data transfer
Important Specifications
| Specification | Details |
|---|---|
| Connector Type | 4-pin Berg (Mini Molex) |
| Primary Use | Floppy disk drives |
| Power Rails | +5V and +12V DC |
| Ground Pins | 2 |
| Connector Gender | Female from PSU to male drive connector |
| Data Support | No (power only) |
| Modern Availability | Rare |
What Devices Is the Berg Connector Compatible With?
The Berg connector was designed for:
- 3.5-inch floppy disk drives
- Some internal card readers
- Certain legacy tape drives
- Older industrial computer hardware
- Retro PC systems
Modern SATA SSDs, SATA HDDs, NVMe SSDs, and optical drives do not use this connector.
Advantages
- Compact design for small devices
- Reliable power delivery
- Simple installation
- A keyed connector reduces installation errors
- Proven reliability in legacy systems
Limitations
- Obsolete in modern computers
- Limited compatibility with current hardware
- Usually unavailable on modern PSUs
- Requires adapters when used with newer power supplies
Berg (Floppy) Connector vs Molex Connector
| Feature | Berg Connector | 4-Pin Molex Connector |
|---|---|---|
| Size | Smaller | Larger |
| Pins | 4 | 4 |
| Primary Use | Floppy drives | HDDs, optical drives, accessories |
| Voltage | +5V and +12V | +5V and +12V |
| Modern Usage | Rare | Still found on some PSUs and adapters |
Common Misconceptions
Is the Berg connector the same as a Molex connector?
No. Both deliver +5V and +12V power, but the Berg connector is significantly smaller and intended for floppy drives.
Does the Berg connector transfer data?
No. It supplies power only. Floppy drives use a separate ribbon cable for data communication.
Is it used in modern PCs?
Generally no. Modern systems rely on SATA power connectors, PCIe power connectors, and dedicated motherboard power connectors instead.
Real-World Examples
- Powering a 3.5-inch floppy disk drive in a Windows 98 desktop
- Restoring a retro IBM-compatible PC
- Industrial computers that still use floppy media
- Legacy hardware maintenance and preservation projects
Related Technology Terms
- Molex Connector — A larger 4-pin peripheral power connector for older storage devices.
- SATA Power Connector — The modern power connector for SATA HDDs, SSDs, and optical drives.
- Floppy Disk Drive (FDD) — A storage device that commonly uses a Berg connector for power.
- Power Supply Unit (PSU) — Converts AC power into regulated DC voltages for computer components.
- 24-Pin ATX Connector — The primary motherboard power connector in desktop computers.