The CONTROL DATA® 819-21 Disk Storage Unit provides a per unit capacity of 4.8 billion bits of rotating mass stor
age designed exclusively for the CDC® 7000, CDC CYBER 70 Model 76 and CDC CYBER 176 Computer Systems.

Each unit consists of a cabinet containing, as standard features, a single spindle with a nonremovable disk pack,
associated drive motor, voice coil positioning mechanism, power supply, logic chassis and dual access to the drive.
The recording medium consists of 22 magnetic-oxide coated disks, with 40 data surfaces and one servo surface
containing head-positioning information. Data is recorded at 6000 bits perinch with a track density of384 tracks per
inch, yielding a capacityof 4.8 billion bits per drive.

When configured to a maximum subsystem capacity, consisting of a CDC 7639-22 Mass Storage Controller and
eight 819-21 Disk Storage Units, a total of 38.4 billion bits of data is available, on-line, to the system.

This document is available as a downloadable PDF.

Reference Number :

Date Published : January 1978

Manufacturer : Control Data Corporation

Platform : Control Data

Format : A4 Photocopied Data Sheet