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Selector
Mu I
tip
lexor
Backup
ROAR
Indicating WX
P
=tJ------1 E8
3
GW
Backup
FW
A
X7
W
WI
ROAR
7
0
0
GX
FX
FWX-WX
GWX-WX
W -
Register
CA
+-
W
PK
AA
CA
0
K ..-
W
PK
CK
0
PF
SFG
SHJ
PG
F3
GO
0
UV
WX
PU
U3
U4
CN
FIELD
PRIORITY
CH
CL
Figure 3-40.
ROAR Controls
ROAR is set from many sources.
Let's
first consider the sources shown in
Figure 3-40
<2>.
The sources set all or
some positions of ROAR.
The table in
this
figure will
help explain the speci-
fic positions of Wand X that are set
from each source.
The source CA->W is an expression
found in a micro program that causes
control lines to be brought up and gate
the CA control field SAL output to the
W-register.
Notice in the table that
the parity bit for W, P, is set by PRe
PR is the parity position for the CK
field and is used because the CA field
has no parity bit of its own.
The W3
position is determined by the one bit AA
field.
Note.
The W3 bit is set when in
1401 mode-iO address a second 4R ROS
module.
Acornplete description of 1401
mode operation is found in the Special
Feature section.
The remaining posi-
tions of the "-register, W4 through 7
CA
I
CK
I
GI
lJ5
P
0
TI
X
Address
Decode
OR
X - Register
CA
CA
2
3
CK
CK
2
3
G2
G3
PH
PJ
HO
HI
H2
H3
JO
JI
J2
J3
U6
U7
PV
VO
VI
V2
V3
V4
V5
V6
V7
PN
CN
eN
CN
CN
CN
CN
0
1
2
3
4
5
X
X
X
X
X
X
X
X
X
X
X
are set from the CA 0 through 3 SAL
outputs.
XI
The R->" expression is similar to
CA->W, except that the "-register is set
from theCR field SAL output.
Switches F, G, Hand
J
are used to
set the ROAR also.
Each position on a
switch provides five output lines when
decoded.
The lines are 0, 1, 2, 3 and a
parity line.
The
0
through
3
lines can
handle any
value from
0 through F in
hexadecimal.
As an example: If switch G
is set to position A, the lines 0
through 3 would contain the value 1010.
1010 is A in hexadecimal.
Refer to the table in Figure 3-40 to
see the switch control of ROAR.
The
parity position of the "-register is set
from the parity lines of switch F and
switch G.
The "3
position is set from
line 3 of switchF.
The "4
through W7
positions are set
by
switch Glines
0
3-61
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