First progress report on a multi-channel magnetic drum inner ...

VIII-2
namely heads are operating at not more than 1/5 their limiting
speed, Wiile pulse packing density and linear velocity could both
probably be doubled which would then approach limits of the
head and circuit.
d) A system of 40 odd channels can be built in quite reasonable
length—about a foot—without introducing any new types of
complications
e) Convenient shaft speeds (6000-BOOO RPM) and drum diameters
(6-8 inches) promise to achieve more than enough capacity of
scanned magnetizeable area.
3) The structure and general expectations of the magnetic drum
proper, together with the forty odd reading-recording heads are now fairly
well fixed; in fact, they have been built and are presently being assembled
and tested and will be discussed in all structural details in the next
section. Deferring these details, consider now how such a drum and head
system may be operated when completed. Block diagrams I and II indicate
in approximate form two modes of operation, which may be seen to be of
parallel and of series types. The merits of each deserve consideration.
A) Both systems have in cosnmon a counter associated with the timing
channel located on the drum. The timing channel could be any sort of
geometrical marker rigidly attached to the drum system and having M segments
clearly and evenly defined; one of the most convenient and simple of such