AccessionIndex: TCD-SCSS-T.20121208.028 Accession Date: 8-Dec-2012 Accession By: Tom Kearney Object name: Magnetic Peripherals Inc Storage Module Drive Vintage: c.1975 Synopsis: 14-inch cartridge disk drive. S/N: 652128.
Description: Magnetic Peripherals Inc (MPI), of Minneapolis, Minnesota , was a joint venture formed by Control Data Corporation (CDC) and Honeywell Bull in 1975. CDC contributed their disk drive facilities at Normandale and Omaha, USA. Honeywell contributed its ex-GE disk plant at Oklahoma City and CII-Honeywell Bull’s plant at Heppenheim, Germany. Its early products were IBM-3330-like third generation disk drives, superceded by IBM-3340/3350/3370-like drives, all with IBM interfaces or Storage Module Device (SMD) interfaces. It became a major player in the hard disk drive market. It was the world wide leader in 14-inch disk drive technology in the OEM marketplace in the 1970s and early 1980s, especially with its SMD and CMD (Cartridge Module Drive) interfaces, and with its 24-hour/7-days-a-week plant at Brynmawr in South Wales, which celebrated the production of 1 million disks and 3 million magnetic tapes in Oct-1979. MPI was renamed Imprimus in 1988 and was bought by Seagate in 1989.
The drive in this collection looks almost identical to a CDC9762 80MB disk drive, introduced in 1974 by CDC, see Figures 21 and 22. However, the drive in this collection was made in Portugal by Magnetic Peripherals Inc, and from the rear can be seen to have a different interface, which looks very like an SMD interface.
The CDC 9762 had five 14-inch 6000 BPI platters. The top and bottom platters were guard platters and not used for storage. The top guard platter was exactly the same size as the data platters, and was usually made from a data platter which had too many errors to be usable. The bottom guard platter was very slightly larger. The remaining three platters provided five data surfaces and one central servo surface for head positioning. They had 823 cylinders, but their format (e.g. 34 sectors of 512-bytes) was system dependent. SMD disk packs required head alignment for exchange of media between drives.
SMD was derived from the earlier DEC RP0x interface, and became the ANSI X3.91M-1982 standard. Two flat cables, A for control and B for 9.6Mbps data, connected the disk drive to a controller. It was available for most 14-inch and subsequently 8-inch disk drives, but was superceded by SCSI.
Accession Index Object with Identification TCD-SCSS-T.20121208.028 Storage Module Drive. Made in Palmela, Portugal by Magnetic Peripherals Inc. Ident.No: BK5C7D, Series Code: 58, Part No: 82398048. S/N: 652128. Marking on servo drive: Assy 73053304, S/N: 65212
Figure 1: MPI Storage Module Drive three-quarter view
Figure 2: MPI Storage Module Drive front panel
Figure 3: MPI Storage Module Drive rear view
Figure 4: MPI Storage Module Drive disk cartridge compartment
Figure 5: MPI Storage Module Drive disk cartridge compartment closeup
Figure 6: MPI Storage Module Drive disk head recess
Figure 7: MPI Storage Module Drive with cover lifted, three-quarter front view
Figure 8: MPI Storage Module Drive with cover lifted, three-quarter rear view
Figure 9: MPI Storage Module Drive with cover lifted front view
Figure 10: MPI Storage Module Drive rear chassis left view
Figure 11: MPI Storage Module Drive rear chassis right view
Figure 12: MPI Storage Module Drive rear chassis rear view
Figure 13: MPI Storage Module Drive rear cardcage
Figure 14: MPI Storage Module Drive front cardcage
Figure 15: MPI Storage Module Drive rear right closeup
Figure 16: MPI Storage Module Drive rear left closeup
Figure 17: MPI Storage Module Drive rear central mechanism closeup
Figure 18: MPI Storage Module Drive left servomotor closeup Servomotor label says: Assy 73053304, S/N: 65212
Figure 19: MPI Storage Module Drive rear right closeup
Figure 20: MPI Storage Module Drive lower right closeup
Figure 21: MPI Storage Module Drive card cage labels
Figure 22: MPI Storage Module Drive manufacturing label Magnetic Peripherals Inc, A subsidiary of Control Data Corporation European Manufacturing Operations, Palmela, Portugal Storage Module Drive, Ident.No: BK5C7D, Series Code: 58, Part No: 82398048, S/N: 652128 Volts: 220, Hz: 50, Ph: 1, A/Ph: 5.0, Watts: 1000, Wire + Ground: 2
Figure 23: Photo of a CDC9762 disk drive for comparison, front view
Figure 24: Photo of a CDC9762 disk drive for comparison, side view