Control Data Cyber 170 State Hardware Reference Manual page 128

CP Set lnstructions
76i jk Set X i t o ( B j )
+
(Bk) SXi Bj
+
Bk
This i n s t r u c t i o n r e a d s operands from
B j
and
Bk,
adds the
operands, and d e l i v e r s
t h e r e s u l t t o X i .
The
sum i s formed i n an 18-bit o n e ' s complement mode. The
18-bit r e s u l t
i s
sign-extended by copying t h e highest-order b i t of t h e r e s u l t
i n t o t h e upper 42 b i t p o s i t i o n s i n X i .
7 7 i j k Set X i t o (Bj)
-
(Bk) SXi B j
-
Bk
This i n s t r u c t i o n r e a d s operands from B j and
Bk,
s u b t r a c t s t h e Bk operand from
t h e B j operand, and d e l i v e r s t h e r e s u l t t o X i . The d i f f e r e n c e i s formed i n an
18-bit o n e ' s complement mode. The 18-bit r e s u l t i s sign-extended by copying
t h e highest-order b i t of t h e r e s u l t i n t o t h e upper 42 b i t p o s i t i o n s i n X i .