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2.
r--~----T----l
1
I
I
IPSW
l_--.L ____
.L ____
J
t
This field is referred to as the
------
--------.
3.
The keys in question
1
can be
changed only by ________ __
4.
Bits
8-11
of the PSW can be changed
only by
(1)
or by (2) _____ _
5.
Storage protection applies to:
6.
7.
8.
a.
Modify-type main storage cycles
b.
Fetch-type main storage cycles
c.
All main storage cycles
Storage Block
A
B
C
o
Rey
o
1
2
3
Assuming a PSW key of 2:
a.
From which blocks may informa-
tion be fetched? ________ __
b.
In which blocks may information
be altered? ________ __
Storage Block
A
B
C
o
Rey
o
1
2
3
Assuming aPSW key of 0:
a.
From which blocks may informa-
tion be read out?
b.
In which blocks may information
be altered?
Storage Block
Rey
A
0
B
1
C
2
0
3
If an instruction with a PSW key of
3 attempts to alter data in block
c:
a.
The data will be stored and the
program will continue.
b.
The data will be stored and the
program will be interrupted.
c.
The data will not be stored and
the program will continue.
d.
The data will not be stored and
the program will be
interrupted.
9.
In the following example, the
(storage/protection) key of block
(A,B,C,D) will be set to
Storage Block
A 6144-8191
B 4096-6143
C
2048-4095
o
0000-2047
Rey
o
1
2
3
Instruction
0 8 4 6
Register 4
0 0 0 0
2 1 4 0
Register 6
0 0 0 0
0 E F 2
10.
Show the register contents after
executing the insert storage key
instruction.
Storage Blank
Rey
A 6144-8191
9
B 4096-6143
8
C 2048-4095
7
D 0000-2047
A
Instruction 0 9 2 3
Register
2
before
o
0 0 0
o
F 0 0
Register
2
after
Register
3
before
o
0 0 0
o
F 0 0
Register
3
after
1-75
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