Seagate ST-157A 45MB 3.5 IDE Half-Height Hard Drive HH Vintage MFM XT

Seagate ST-157A 45MB 3.5 IDE Half-Height Hard Drive HH Vintage MFM XT

The Seagate ST-157A is a 45MB 3.5-inch half-height IDE hard drive from the early era of IDE (ATA) storage. Assembled in Thailand, this drive uses a half-height form factor and connects via the standard 40-pin IDE interface. It draws power from a standard 4-pin Molex connector rated at +5V/1.0A and +12V/2.0A.

Specifications & What's Included

• Make: Seagate
• Model: ST-157A
• Capacity: 45 MB
• Form Factor: 3.5-inch Half-Height (HH)
• Interface: IDE (ATA), 40-pin connector
• Power: +5V / 1.0A, +12V / 2.0A (standard 4-pin Molex)
• Country of Assembly: Thailand
• Certifications: UL, SA (APL) — visible on label
• Controller PCB: integrated, mounted to underside of drive
• Included: drive only

Applications

The Seagate ST-157A dates from the late 1980s, the period when IDE (AT Attachment) was displacing earlier interfaces like MFM and RLL in desktop PCs. At 45MB, this drive was a mid-range capacity unit for its era, suitable for IBM PC/AT-compatible systems running MS-DOS. Today the ST-157A is sought after primarily for vintage PC restoration and retro computing projects — it is one of the early native IDE drives that collectors use to return period-correct machines (286 and early 386-era PCs) to working condition. It also appears in industrial and embedded systems from the same era that used standard IDE storage and have not been upgraded.