Singer 40 - General Description of Models 40 and 42 Disc Drives; Model 40 Disc Drive Features

1 GENERAL DESCRIPTION
The Models 40 and 42 Disc Drives are high speed, random access storage
devices designed as peripheral units for the System Ten* computer. Up to ten
disc drives may be attached to the central processor through the File Access
Channel (F AC). A Disc Controller, consisting of printed circuit cards con-
tained in the central processor, acts as intermediary between the disc drives
and the F AC. A particular installation may include both models in any combi-
nation. In external appearance, the two models are identical (see Figure 1-1);
what differentiates them is the type of disc pack used. Both models use
removable disc packs.
The Model 40 uses a disc pack consisting of six magnetic oxide coated discs
joined to one another on a common vertical axis. The discs are approximately
14 inches in diameter and there is approximately .4 inches between successive
discs. The disc pack (Model 41 Disc Pack) has ten recording surfaces. The
top surface of the top disc and the bottom surface of the bottom disc are not
used for recording data.
Figure 1-1. Model 40 Disc Drive
*A trademark of The Singer Company
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Models 40 and 42 Reference Manual 1-1