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16K AUXILIARY STORAGE
•
Auxiliary storage in the 16K storage unit consists of
four 256-byte storage areas.
•
The eight additional Y-lines intersect with 128 X-lines
in each plane to produce 1024 additional storage positions.
•
Two additional Y-read gates and two additional Y-write gates
control the additional Y-lines.
The 16K auxiliary storage unit uses the
same additional Y-line bump decode drivers
shown in Figure 2-80.
These drivers are
controlled by the M-register 3-bit (MM152).
In the 16K storage unit the X-lines undergo
32K STORAGE OPERATION
a phase reversal between 8K units.
Be-
cause of this phase reversal, selection of
an auxiliary storage position requires X-
line phase reversal control using the M-
register 2-bit (MM232).
•
One single set of Y-lines drives all -18 core planes.
•
Two sets of X-lines drive 18 core planes.
•
Phase reversal takes place between the first and second
8K on the first set of X-lines, and between the third
and fourth 8K on the second set of X-lines.
Description
The 32K storage unit consists of 18 core
planes.
The Y-windings go through all 18
planes in a serial manner (see Figure 2-69).
There are two sets of X-windings;
one for
the first 16K, and one for the second 16K.
In each 16K, the X-winding undergoes a
phase reversal between 8K units.
Selection
Circuit Objectives
Circuit control for 32K takes place at the
X-contr.ol drivers and X-source drivers.
The M-register 2- and l-bits select the
appropriate set of control drivers (0-16K,
l6-32K), and determine the direction of
current flow by controlling the X-source
drivers.
1.
Select the appropriate set of X-control
drivers.
The M-register 2-bit and 1-
bit determines which set (first 16K or
second 16K) of X-control drivers is
used (MM232, MM242).
M Reg 1 Bit
M Reg 2 Bit
Rd 1
Write A
2-90
of a single core storage position requires
control of drive current direction for the
phase reversal.
This control uses the M-
register 2- and l-bits to determine which
X-control drivers and X-source drivers are
turned on.
2.
Control the direction of current flow
according to the 8K unit being selected
and whether the operation
is
read or
wri te (MM252).
Go
X-Source Write
M Reg 2 Bit
X-Source Read
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