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IBM 7090 User Manual

IBM 7090
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Load
Index
from
Decrement
LXD
-0534
(I, E)
Figure
5.3-66
This
instruction
loads
the
specified
index
register
with
the
contents
of
the
decrement
field
(3-17) of
storage
location
X
in
true
form.
Execution
of LXD
is
identical
to
that
of
LDC,
except
that
the
complementing
operation
is
not
used.
5.3.
11
AND
and
OR
Instructions
The
AND
and
OR
instructions
are
used
to
produce
logical
combinations
of
bits.
These
are
useful
for
masking
or
matching
words.
OR
to
Storage
ORS
-0602
(I, E)
Figure
5.3-67
This
instruction
stores
the
logical
OR of
the
word
stored
at
location
X
and
the
AC
(P,I-35)
in
location
X.
The
logical
OR
is
obtained
by
matching
the
two
words
and
stor-
ing
ones
in
all
positions
which
have
ones
in
either
word.
For
this
instruction,
the
OR
is
developed
in
the
memory
data
register
during
the
E
cycle.
The
words
from
core
stor-
age
and
the
SB
both
go
the
memory
data
register
and
the
result
in
the
memory
data
regis-
ter
is
put
back
into
core
storage.
OR
to
Accumulator
ORA
-0501
(I,
E)
Figure
5.
3-68
This
instruction
places
the
logical
OR
of
the
word
stored
at
locationX
andAC(P-35)
in
the
accumulator.
The
OR
is
produced
by
matching
the
two
words
and
placing
ones
in
all
positions
of
the
AC
which
have
ones
in
either
word.
The
OR
is
developed
in
the
SR
by
gating
both
the
storage
and
AC
words
into
the
SR
at
the
same
time.
Sand
Q
remain
unchanged.
AND
to
Accumulator
ANA
-0320
(I,
E,
L)
Figure
5.3-69
This
instruction
places
the
logical
AND
of
the
word
stored
at
location
X
and
the
AC
(P,
1-35)
in
the
accumulator
(P,I-35).
The
logical
AND
is
obtained
by
matching
the
two
words
and
placing
ones
in
all
positions
of
the
accumulator
which
have
corresponding
ones
in
both
the
AC
and
storage.
This
instruction
is
executed
by
OR'ing
the
complement
of
both
words
and
then
complementing
this
sum.
AND
to
Storage
ANS +0320 (I,
E,
L,
E)
Figure
5.3-69
This
instruction
stores
the
logical
AND of
the
word
stored
at
location
X
and
the
contents
of
the
AC
(P,
1-35)
in
location
X.
The
logical
AND
is
obtained
by
matching
the
two
words
and
placing
ones
in
all
positions
of
storage
location
X
which
have
corre-
sponding
ones
in
both
the
AC
and
storage.
The
contents
of
the
AC(S, Q,
P,
1-35)
are
un-
changed.
The
AND
is
accomplished
the
same
for
this
instruction
as
for
ANA. An
addi-
tionalE
cycle
is
requiredto
put
the
AND
in
storage.
The
complement
of
the
original
AC
(P,
1-35)
is
returned
to
the
AC
and
re-complemented
to
trestore
the
contents
of
AC
(P,
1-35).
During
the
execution,
the
original
AC(Q)
is
saved
in
SR(Q)
and
then
returned
to
AC(Q).
Exclusive
OR
to
Accumulator
ERA
+0322 (I,
E,
L)
Figu:r:e
5.3-70
This
instruction
matches
AC(P,
1-35)
with
the
logical
word
stored
at
location
X.
Zeros
replace
all
positions
of
the
AC
which
match
the
corresponding
positions
of
the
logical
word.
Accumulator
positions
(S)
and
(Q)
are
cleared.
128

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IBM 7090 Specifications

General IconGeneral
CategoryMainframe Computer
Introduced1959
Transistor-basedYes
Word Length36 bits
Add Time4.8 microseconds
MemoryCore memory
Memory (words)32, 768 words