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[ IDENTIFIED PC FLOPPY DRIVE ]

Alps DFC642B09A 1.2 MB 5.25-inch drive

A half-height Alps double-sided high-density mechanism. The exact suffix DFC642B09A is the identifying SKU; use the PCB markings and drive-specific jumper chart rather than generic Alps-family assumptions.

Original local schematic of the Alps DFC642B09A floppy drive, not to scale
ORIGINAL LOCAL SVG // SCHEMATIC, NOT TO SCALE

Documented specifications

Density / capacityDouble-sided 5.25-inch HD mechanism; 1.2 MB formatted HD and 360 KB DD compatibility when controller, media, and alignment permit.
Interface34-pin PC floppy ribbon interface and 4-pin +5 V/+12 V power connector.
Data rate / speed500 kbit/s HD; 250 kbit/s DD controller mode; 360 rpm HD. Confirm DD speed and supported mode from the fitted PCB/manual.
Jumpers / drive selectDrive-select DS0–DS3 and termination/configuration jumpers vary by board. Select one PC drive line and consult the jumper reference for this exact PCB; no generic jumper position is assumed here.
Dimensions / powerHalf-height, approximately 146 × 41 × 203 mm; +5 V and +12 V through a 4-pin connector. Current specifications are revision-dependent and should be checked against the unit label/service documentation.
PC controller compatibilityStandard PC/AT-compatible 765-family controllers support the 34-pin interface in 1.2 MB mode; controller BIOS and drive-select/cable setup must match.

Preservation notes

Photograph the full label and PCB jumper legends before installation. Check the resistor pack, spindle speed and head condition; avoid alignment adjustments until known-good reference media and a suitable test setup are available.

Manuals & archive sources

  1. 5.25-inch floppy drive jumper referenceArchival configuration guide; use only after matching the board and option legends.
  2. 5.25-inch floppy drive documentation archivePreserved model/reference collection for period 5.25-inch drives and service material.
  3. Alps DFC642B09A model listing and specificationsSKU-specific identification and PC capacity/interface details; confirm values against the actual unit.