Computer Options - Varian Data 620/i System Reference Manual

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5
4 3 2 1 0
r - T -
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L_l_l
00
6 Op Code 0
n+l
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Operand
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option
Figure 2-7. Double-Word Instruction Format, Immediate Type Instructions
2.3 COMPUTER
OPTIONS
The following options can be mounted in the basic computer
rack.
620/i-10 This option provides three additional features
for the computer. These are: multiply, divide,
and extended addressing.
During multiply, the contents of the B register
are multiplied by the contents of a specified
memory location. The original contents of the
A register are added to the final product.
Execution time is 18 microseconds for the basic
16-bit computer; 19.8 microseconds for the
l8-bit model.
During divide, the contents of the A and B registers
are divided by the contents of a specified memory
location. Execution time is 18 to 25.2 micro-
seconds for the basic l6-bit computer; 19.8 to
28.8 mi croseconds for the l8-bit model.
During extended addressing, all single-word
instructions can be programmed as double-word
instructions, where the second word contains
the effective address of the operand. This option
is used with the basic DATA 620/i-00.
2-11