CDC 12 platter combination Unit
Part Number: 40052099
Serial number: 970946

Thanks to David Jones who has informed us that it was used in a CDC 9766 300MB drive, and to Malcolm Gill for adding that it was used in the 9764.

The Control Data Storage Module Drives (SMD) are random-access rotating memories which use removable disk packs as their storage media. This SMD family is comprised of the CDC" 9760 (40 MB), 9762 (80 MB), 9764 (150 MB), and the 9766 (300 MB) Drives.

The basic drive unit has four main components: Power supply, logic chassis, air filtration, and deck. The deck holds the drive spindle assembly and voice coil positioning mechanism. Head positioning is performed by a closed-loop, proportional servo system driving a voice coil linear actuator.

Family characteristics within this SMD series include common styling, common interface and identical transfer rates (compatible formats). These features allow greater system flexibility and permit the use of common spare parts and test equipment.

This SMD family incorporates the most advanced technology available and provides high performance, high reliability, and high accessibility.

STANDARD FEATURES

•  I/O connectors suitable for flat cable
•  Pluggable power supply
•  Phase-locked oscillator/data separator
•  NRZ to MFM data encoder with write compensation
•  Daisy chaining of up to 16 drives
•  Address mark detection for variable sectoring
•  Switch-selectable fixed sectoring
•  Spindle brake
•  Write protect