IBM 1620 1 Manual page 12

Appendix A. The symbols used in the formulas are
defined as follows:
Dp Number of digits, including high-order
zeros, in the field at the P address.
Dq Number of digits, including high-order
zeros, in the field at the
Q
address.
Dq' Number of digits, including high-order
zeros, in the data field of an immediate
instruction.
Dz Number of positions compared, prior to
the detection of a digit other than zero.
T Time in microseconds ( {J-sec ) or milli-
seconds (ms), as noted.
Additional symbols used only in Load Dividend, Load
Dividend Immediate, Divide, and Divide Immediate
instructions are defined under Execution Time, follow-
ing the explanation of the individual instruction.
Immediate Instructions
Certain arithmetic, internal data transmissions, com-
pare, and branch instructions are labeled "immediate."
Immediate instructions use the digits in the
Q7, Qs,
Q9, QlO
and
Ql1
positions of the instruc,:tiOn as data
instead of as a core storage address. .
Thus, the
Q
data is located immediately within the
instruction. For example, when the Transmit Field
Immediate instruction, 16 00543 18765, is executed,
the Q part of the instruction, 18765, is transmitted to
the P address (Figure 5). Data transfer begins at
Ql1
of the instruction, and continues until a flag bit is
found,
Q7 in this case. If the flag bit was at QI0,
65
would be transferred to 00543. The difference be-
tween the Transmit Field and Transmit Field Imme-
diate instructions can best be shown by comparing
Figures 5 and 6. The Transmit Field instruction,
Figure 6, tranfers the data at the Q address to the
P addresses.
8
OP
Code P Address
Q
Address
1116101015141311/81716151
I I I
------------~
Core Storage
Figure 5. Transmit Field Immediate - Data Flow
OP
Code P Address
Q
Address
121610101514131118171615\
I~I~
Core Storage
~ ~
&
294
~
I
Figure 6.
Transmit Field - Data Flow