[ INDIVIDUAL COMPONENT // HARD DISK DRIVES ]
Seagate ST-225
5.25-inch half-height MFM HDD, 1980s. This record describes this specific product, standard, or clearly identified family; it is not a claim that every product sold under a similar name shares these specifications.
IDENTIFICATION WARNING: Match the complete model/part number and revision to its label and manual. Family-level entries may cover revisions; values marked “common” are not guaranteed for every unit.
Specifications
| Catalog subcategory | MFM and early magnetic drives |
|---|---|
| Catalog identity | Seagate ST-225 |
| Era / family | 5.25-inch half-height MFM HDD, 1980s |
| Key specifications | 20 MB formatted capacity; ST-506/ST-412-compatible interface; 615 cylinders and 4 heads in common geometry |
| Interfaces / mechanical | Requires a compatible MFM controller, cabling, low-level format, and drive-specific geometry |
| Compatibility and variants | Controller BIOS/drive geometry and interleave affect usable performance and compatibility. |
| Use / service note | Inspect condition, revision markings, firmware or configuration, connectors, and any prior repair. For preservation, record photographs of labels and board markings before cleaning or disassembly. |
Identification & compatibility checks
- Photograph manufacturer, full model number, revision, serial/date codes, connector faces, and included brackets or cables before installation.
- Confirm electrical interface, connector pinout, physical dimensions, power requirements, firmware/driver support, and the host device’s documented compatibility.
- Do not infer compatibility from a shared brand, socket silhouette, connector shape, or marketing family name. Revisions and regional SKUs may differ.
- When a unit’s identity is uncertain, compare component markings against the manufacturer manual and avoid applying power until the pinout and condition are known.
Context & archival notes
Controller BIOS/drive geometry and interleave affect usable performance and compatibility.
Useful collection fields: exact model and revision; manufacture date; board/assembly identifiers; firmware; accessories; condition; known faults; source of acquisition; and the document revision used to verify this entry. Any measured result should include test setup and method.
Sources & further reading
- Seagate Support — Drive documentationPrimary or standards reference for this component family; confirm the full model number and revision.
- SATA-IO — SATA specificationsPrimary or standards reference for this component family; confirm the full model number and revision.
Source notes point to standards bodies, manufacturers, or archival records. Some sources cover a family rather than this exact revision; the manufacturer datasheet/manual for the full part number takes precedence.