<s>
The	O
Burroughs	O
B5000	O
was	O
the	O
first	O
stack	B-Application
machine	I-Application
and	O
also	O
the	O
first	O
computer	O
with	O
a	O
segmented	B-General_Concept
virtual	B-Architecture
memory	I-Architecture
.	O
</s>
<s>
The	O
Burroughs	O
B5000	B-Device
instruction	I-Device
set	I-Device
includes	O
the	O
set	O
of	O
valid	O
operations	O
for	O
the	O
B5000	O
,	O
B5500	O
and	O
B5700	O
.	O
</s>
<s>
Instruction	O
streams	O
on	O
a	O
B5000	O
contain	O
12-bit	O
syllables	B-General_Concept
,	O
four	O
to	O
a	O
word	O
.	O
</s>
<s>
The	O
architecture	O
has	O
two	O
modes	O
,	O
Word	O
Mode	O
and	O
Character	O
Mode	O
,	O
and	O
each	O
has	O
a	O
separate	O
repertoire	O
of	O
syllables	B-General_Concept
.	O
</s>
<s>
A	O
processor	O
may	O
be	O
either	O
Control	O
State	O
or	O
Normal	O
State	O
,	O
and	O
certain	O
syllables	B-General_Concept
are	O
only	O
permissible	O
in	O
Control	O
State	O
.	O
</s>
<s>
Burroughs	O
numbers	O
bits	O
in	O
a	O
syllable	B-General_Concept
from	O
0	O
(	O
high	O
bit	O
)	O
to	O
11	O
(	O
low	O
bit	O
)	O
and	O
in	O
a	O
word	O
from	O
0	O
(	O
high	O
bit	O
)	O
to	O
47	O
(	O
low	O
bit	O
)	O
.	O
</s>
<s>
In	O
Word	O
Mode	O
,	O
there	O
are	O
four	O
types	O
of	O
syllables	B-General_Concept
.	O
</s>
