ST-225 (Hard Drive) (1986)

ST-225 (Hard Drive) (1986)
  • Model: Seagate ST-225
  • Manufacturer: Seagate
  • Released in: 1986
  • Capacity: 20MB
  • CMOS type: 2


  • Rotational Speed: 3,600 RPM ± 1%
  • Recording Density: 9,827 BPI (Cylinder 614) 
  • Flux Density: 9,827 FCI(Cylinder 614)
  • Track Density:588 TPI
  • Cylinders: 615 
  • Tracks:2,460 
  • Read/Write Heads: 4
  • Discs: 2
  • Data Transfer Rate:5.0 Megabits/second 
  • Recording Scheme: MFM
  • Height: I.63 Inches max.. (41.4mm)
  • Width:5.75 inches (146.05mm)
  • Depth:8.00 inches  max. {203.2mm)
  • Weight: 2.75 Ibs (1.25KG)


The Seagate ST225 disc drive provides Original Equipment Manufactures and system integrators with over 20 megabytes of formatted capacity in a shock-resistant half-height package. The ST225 is designed for single-user desktop systems, local storage in-network or multi-user systems, Or as an add-in upgrade for PCs. The low-power ST225 design is ideal for these applications in either rugged industrial or quiet office environments. The ST225 supports the industry-standard ST412 interface and has the same voltage requirements for ease of integration.

High reliability is assured through the use of Large Scale Integration, a single printed circuit board, mini-monolithic heads, and proven oxide media. Scagate’s proprietary helical-band rotary-actuator features simplicity and ease of manufacture with excellent thermal stability. A dedicated head shipping zone assures data integrity during shipping and handling. The ST225 offers a low-cost, rugged, and reliable disc drive with an MTBF of 20,000 hours