[ INDIVIDUAL COMPONENT // FLOPPY DRIVES ]
Y-E Data YD-702D 3.5-inch Floppy Mechanism
An internal 3.5-inch magnetic disk mechanism cataloged by its complete model code. Product-family similarity is not proof of identical wiring, media support, board straps or mechanical fit.
MODEL IDENTIFICATION: Y-E Data YD-702D. Confirm the complete label and board revision before wiring, servicing, or media access. Approximate dimensions and common PC-format operation do not replace the suffix-specific source drawings.
Documented mechanism characteristics
| Manufacturer / exact model | Y-E Data / YD-702D |
|---|---|
| Capacity and format | 3.5-inch double-sided mechanism supporting 2HD/1.44 MB and 2DD/720 KB formats; some documented configurations add non-PC 1.6 MB or 1.0 MB modes. |
| Interface and power | 34-pin floppy-control interface with separate DC power; expanded modes may require the correct host/controller signals and media. |
| Data rate | PC HD/DD formats use 500/250 kbit/s respectively. Extended-format rates and sector layouts are controller-specific; do not assume PC BIOS support. |
| Mechanical dimensions (W × H × D) | Approx. 101.6 × 25.4 × 145 mm (W × H × D); confirm the mounting drawing and full suffix. |
| Jumpers / drive select | The 702D series manual documents capacity/mode and drive-select configuration. Match the exact suffix and host requirements to its setting table; preserve the original strap positions. |
Controller and cable compatibility
- For ordinary PC use, confirm the controller supports the selected 3.5-inch format and rate, and use a correctly keyed 34-pin ribbon with the correct pin-1 orientation and separate drive power.
- On conventional PC twisted-ribbon cabling, cable position and drive-select straps work together to establish A:/B: addressing; untwisted systems may use different DS settings. Follow both the drive manual and host/controller documentation.
- Do not assume DOS/BIOS support for extended formats, three-mode disks, non-PC READY/disk-change behavior, or flux-level preservation from the 34-pin connector alone. Verify electrical signals and controller capability first.
Preservation and service cautions
- Inspect media for mold, oxide shedding, a damaged shutter, or debris; never insert visibly damaged media into a valued mechanism.
- Do not force the eject mechanism, move the head by hand, lubricate by guesswork, or adjust alignment without the matching service procedure and calibration equipment.
- Before cleaning/service, photograph the full label, board revision, straps, cable orientation and host setup. Preserve original media and raw disk images; verify copies and record checksums separately.
- Use known-good expendable media and stop on abnormal noise, repeated retries, head contamination or unstable reads. A filesystem copy may omit weak bits, unusual formats and copy-protection data.
Manufacturer / service-manual sources
- Y-E Data — 702D Series floppy disk drive user manualSeries user/installation manual with settings and mode information.
- Y-E Data YD-702D-6639D — model identification and specificationsSpecific YD-702D variant listing; check exact suffix against the label.
- IBM — Personal Computer Technical ReferencePC controller/cable baseline; does not describe non-PC modes.
Follow model- and revision-specific documentation. Related-family manuals provide context only where explicitly noted and must not be treated as interchangeable service instructions.