Control Data Cyber 170 State Hardware Reference Manual page 188

CP Programming
Nonstandard Operands
In summary, the special operand forms in octal are:
Positive overflow (+ ) 3777x,...,x
Negative overflow (- ) 4OOOx,
...,
x
Positive indefinite (+IND) 1777x,...,x
Negative indefinite (-IND) 6OOOx,
...,
x
Positive underflow
(+0)
OOOOx,...,x
Negative underflow (-0) 7777x,.
. .
,x
Tables
5-2
through 5-5 indicate the resulting forms when various combinations
of underflow, overflow, and indefinite forms are used in floating-point
operations. The designations W and N are defined as follows:
W Any word except
+
co
and
+
IND
N Any word except
+
o,
,
+
IND,
and
+
0
Table
5-2. Xj Plus Xk (30, 32, 34 Instructions)
IND IND IND