Table of Contents
Advertisement
The 20 digits of the area in core storage specified as
the "product area" (positions 00080 through 00099)
are automatically cleared to zeros before multiplica-
tion begins. Formation of the product then proceeds
serially from right to left until terminated by the
flag bit marking the high-order position of the field
at the
Q
address. A flag bit is stored in the high-order
position of the product, and the sign of the product
is indicated by the presence (negative) or absence
(positive) of a flag bit in position 00099. A zero prod-
uct may have a negative or positive sign, depending
upon the signs of the fields at the
Q
and P addresses.
The number of digits in the product is equal to
the sum of the digits (high-order zeros included) in
the fields at the
Q
and P addresses. The size of the
product is limited only by the core storage positions
available. A product longer than the 20 positions of
the product area may be formed, but positions in
excess of 20 digits must be cleared to zeros by pro-
gram instructions preceding the Multiply instruction.
It is possible to develop a product so large that it
extends from its units position (location 00099), left-
16
ward to location 00000, continues at the highest-order
core storage location (19999, 39999, or 59999), and
finally terminates with its high-order digit at some
location lower than the highest-order location. The
Arithmetic Check indicator is not turned on when the
product exceeds 20 digits in length. The
H/P
indicator
is on if the product is positive and not zero; the
E/Z
indicator is on if the product is zero. Neither indicator
is on if the product is negative.
Execution Time. The execution time varies accord-
ing to the number of digits in the fields at the
Q
and
P addresses.
T
==
560
+
40D q
+
168 DqDp
fJ-sec
Multiply
Immediate
(MM-13)
Description. The description for Multiply (M -23 )
applies except that the data in the
Q
part of the in-
struction is used in place of the data in the field at
the
Q
address.
Execution Time. T
==
560
+
40D/
+
168Dq'D p
fJ-sec
Advertisement
Table of Contents
