PATA Device Cables

Aug 21, 2025

Overview

This lecture covers Parallel ATA (PATA), its history, types of cables used, device connections, and distinguishing features of this legacy storage interface.

PATA Overview and History

  • PATA stands for Parallel ATA, also known as Parallel AT Attachment, and was originally called IDE (Integrated Drive Electronics).
  • The term AT Attachment comes from IBM's PC AT system which used this drive connection standard.
  • Western Digital coined the term IDE, later updated to Enhanced IDE (E-IDE).
  • PATA supports throughput speeds ranging from 16 MB/s to 133 MB/s.
  • Devices supported by PATA include hard drives, CD-ROMs, and DVD-ROMs.

PATA Cables and Connectors

  • There are two main PATA cables: a 40-wire cable and an 80-wire cable, both with 40-pin connectors.
  • The 40-wire cable is the original; the 80-wire cable was introduced to reduce crosstalk at higher speeds, doubling the wires but keeping the same connector.
  • On the 40-wire cable, device 0 connects first, with device 1 at the end; on the 80-wire cable, this order is reversed.
  • PATA connectors are large compared to SATA connectors, making them easy to identify inside systems.

Physical Characteristics and Orientation

  • All PATA cables and motherboard/device connectors are 40-pin and symmetrical.
  • One pin is intentionally missing from the connector to prevent incorrect insertion.
  • Notches on the connector and cable further ensure proper orientation when plugging in.

Legacy Status and Comparison to SATA

  • PATA is considered legacy technology, rarely found in modern systems.
  • PATA ribbon cables are much larger and bulkier than SATA cables, which are used in newer computers.

Key Terms & Definitions

  • PATA (Parallel ATA) — Legacy interface for connecting storage devices using parallel signaling.
  • IDE (Integrated Drive Electronics) — Original term for PATA, describing drives with built-in controller electronics.
  • E-IDE (Enhanced IDE) — Improved version of IDE supporting faster speeds and more devices.
  • Crosstalk — Electrical interference between wires, reduced by using 80-wire PATA cables.
  • SATA (Serial ATA) — Modern, smaller, and faster replacement for PATA.

Action Items / Next Steps

  • Identify and label any ribbon cables inside legacy equipment.
  • Read about the transition from PATA to SATA in your textbook.

Full transcript