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Subtraction
An instruction containing the operation "
-
" directs the computer to subtract the contents of
the selected register (subtrahend) from the contents of the A register (minuend) and is
executed in two phaaes:
1ST PHASE
Transfer the contents of the selected register (subtrahend) to II, while
ratalnlng them In the original register.
2ND PHASE
Subtract the contents of M from the contents of A (minuend) obtaining in
A the difference truncated according to the setting of the Decima/ Wheel.
The complete difference is in R. M contains the subtrahend.
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RESULTS
INSTRUCTION PHASE 1 PHASE 2 TRUNCATED COMPLETE
____________
A-M
A
R
R-
R
M
A-M
A
R
A-
A
M
A-M
A
R
b -
b
M
A-M
A
R
B-
B
M
A-M
A
R
c -
c
M
A-M
A
R
C-
C
M
A-M
A
R
d -
d
M
A-M
A
R
D-
D
M
A-M
A
R
e -
e
M
A-M
A
R
E-
E
M
A-M
A
R
f -
f
M
A-M
A
R
F -
F
M
A-M
A
R
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EXAMPLE:
Decimal Wheel set at 2.
______________________________________
M
A
R B
_
BEFORE
5
7.2567
9.00 3.255
B-
AFTER
3.255 4.00 4.0017 3.255
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An example of using this Instruction manually to subtract 2 factors would be (assume factor 1
(7.2567) is in the b (B/) register and factor 2 (3.255) is in the B register):
Transfer factor 1 to the A register by depressing keys B/
. . . . . . . . . . . . . . . . . . . . . b
Subtract the second factor by depressing keys B- . . . . . . . . . . . . . . . . . . . . . . . . . . . . B -
Print the difference by depressing A
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.0017 A
For this example the Decimal Wheel was set at 4.
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