CDC 94205-51 43MB 5.25" Half-Height MFM Hard Drive HDD PN 77747226

CDC 94205-51 43MB 5.25" Half-Height MFM Hard Drive HDD PN 77747226

The CDC 94205-51 is a 43MB 5.25" half-height MFM (Modified Frequency Modulation) hard disk drive manufactured by Control Data Corporation (CDC), one of the pioneering names in hard drive technology. It uses the ST-506/ST-412 interface standard, which was the dominant hard drive interface for IBM PC, XT, and AT-class systems throughout the early-to-mid 1980s. This drive interfaces with a separate MFM controller card installed in the host system.

Specifications & What's Included

• Manufacturer: Control Data Corporation (CDC) / Magnetic Peripherals Inc.
• Model Number (MN): 94205-51
• Part Number (PN): 77747226
• Capacity: 43 MB
• Form Factor: 5.25" Half-Height
• Interface: MFM (Modified Frequency Modulation), ST-506/ST-412 compatible
• LOT: O-8810 (consistent with late 1988 manufacture date)
• Country of Manufacture: USA
• Includes: Drive only — no cables, controller card, or mounting hardware

Applications

MFM hard drives using the ST-506/ST-412 interface were the standard mass storage solution for IBM PC, PC/XT, and PC/AT compatible systems during the early-to-mid 1980s. The CDC 94205-51 was used in business workstations and personal computers of that era, typically paired with a dedicated MFM controller card (such as those from Western Digital or Seagate). Today these drives are sought after for vintage computer restoration projects — particularly for IBM PC/AT, early Compaq Deskpro, and similar systems that require period-correct MFM storage. The 5.25" half-height form factor fits standard full-size drive bays of the era. MFM was eventually superseded by the RLL, ESDI, and IDE/ATA interfaces in the late 1980s and early 1990s.