Rockwell 24K User manual

GENERAL INFORMATION (3) hours operating time. A dim display I Clear Operations
and Ov e rflow Conditions.
Before Operating Your Calculator:
If a number has been entered in the me-
indicates the batteries are discharged and
recharging is necessary. Your charger is
Charge the batteries. Your Rockwell 24K mory, a Memory Indica
tor dot is display-
not an AC adapter and, consequently,
should
not be , used continuously. Degra-
ca lculator is sup plied with rechargeable
ed in the far left position of the display:
internal batteries a
nd a battery charger. - .123.45678
or .0.3334567, for example.
dation
of the batteries may occur if cha'rg -
To
charge the batteries, simply plug the Arithmetic Function
and Answer Keys
i ng is continued for more than 72 hours.
charger
into the jack provided on' your
The arithmetic function keys, [±] , B '
calrulator and astandard AC outlet.
To avoid possible damage to your calcula-
[K] ,a nd EJ ,enter the desi red arith-
tor,
use only the charger supplied with it.
CAUTION: Do not turn your calculator metic operation
to be performed by the
on until the batteries have been charged
OPERATION calculator. The answer
to such an opera-
for at least 10 minutes. (This applies
tion is obtained by depressing one of the
On/Off Switch
after extended storage
of your calculator
answer keys, El or ~ ,or by another
Turning the calculator on
will automati-
also.) depression
of an arithmetic function key.
cally clear the calculator (including its
Do not operate your calculator without
The decimal
point is automatically placed
memory)
to zero. The calculator is then
the charger
until you have charged the in the correct position in
your answers.
immediately ready
for problem solving.
batteries
for five hours. Failure to do ' so
Clear Key
Display •
may damage the batteries. 1CE/C I .
Depressing the I CE/c i key
1.
Eight-digit display
Your calculator will accept and display
With the calculator
off, allow approxima- clears the display of erroneous entries,
2. f\liemory keys any positive
or negative number between
tely ten (10) hours
for the batteries to ca ' ncels overflow conditions, or clears the
3. Register exchange key and square
0.0000001 and 99,999,999. A negative
be fully charged. You can operate your
calculator of stored numbers and func-
number
is indicated by a minus sign on
root key calculator while charging the batteries but tions. The memory contents
are not ilf-
the left side of the display: -3 .1469782,
4. Percent key and change sign key the time required
for the batteries to be-
rected by depression of the ICE/C I key.
for example. Results in excess of eight
5.
Arithmetic function
keys
come fully charged will increase. When (See Clear Operations for detailed instruc·
digits
cause an overflow condition which
6. Equals key
the batteries are fully charged, at least tions
on use of the I CE/ci key.)
is indicated by illuminatin all eight de-
7. Battery charger jack three hours
of operating time can be
cimal points: 1.2.3.4.5.6.7. 8. ,for ex- Memory
Keys
B. Decimal key expected. ample,
and the eight most significant Yourcalculator
has a completely indepen-
9. Clear entry/clear key Battery Life digits
of your answer are saved . I.n this dent four-key memory. The functions
of
10. On-Off switch Battery life will
be prolonged by recharg- circumstance, all keys become inoperative the memory operation k
eys are : 1M±] and
ing
1he batteriesafter approximately three except the clear key,
ICE/ci . See
1M-I ,Depressing the [ME ,or lliEl '

I
I
I
key adds or subtracts the number in the means
your calculator works the same
display
to, or from, the memory contents. way you think
or wri te a problem.
I
MR 1 Depressing the IMR 1 key recalls the
Notice that
the display shows each new
number
in the memory to the dis- numerical entry as you depress the num-
play. This recalled number may ber
entry keys and the result of the pre-
be used
in subsequent arithmetic vious arithmetic calculation when you
operations. depress an arithmetic function key or
[}J9 Depressing the ~ key clears answer key.
the memory. Addition, Subtraction,Multiplication and
Square Root Key Division
r-r1 Depressing the 1 -r 1 key causes Addition, subtraction, multiplication, and
the calculator to display the square division operations may be itltermixed,
root
of the displayed number.
or chained, as shown below:
Change Sign Key
GEl Depressing the 1 +/-1 key chan~
(5 + 6) J-8
~ 7.6666666
,the sign of the displayed number. Keyboard Entry Display
Percent Key 5 5.
00 The 00 key operates just like the
[fJ6
equal key, 0 ,when multiplying
00
11.
6.
and dividing
except that it causes 7 7.
the last entry to be divided by 100
El
77.
.before the desired arithmetic oper- 8 8.
ation is performed.
I±l
69.
Register Exchange
Key
9
9.
B Depressing the EI key interchang-
El
7.6666666
es
the contents of the display and
out re-entering the numbers each time. multiply each item
in the recipe by 7/4 or I
For example, grocery items with values 1.75, as follows:
of 1.69+2.98 +
2.98 + 2.98 + 0.49 ~ 11.12 6 cups flour x 1.75
~ 10_5 cups flour
would be added as follows: 1.5
tsp salt x 1.75 ~ 2.625 tsp salt
Keyboard Entry Display
2cupsmilkxl.75 ~ 3.5cupsmilk
1.69 1.69 Keyboard Entry Display
[±j2 .98 2.98
6 6.
4_67 o 1.75 1.75
~
7.65
G 10.5
C±J
10.63
1_5
1.5
.49
0.49
G 2.625
11.12
G 2
:2.
Automatic Constant G
3.5
The
automatic constant is another time
saving feature. This feature enables you
In all instances, the constant is retained j!
to add, subtract, multiply or divide by until a different number
is entered after
the same nlllmber repeatedly without re-
an arithmetic function key
is depressed.
entering the number for each new calcula- Percentage Operations
tion. The number entered after
the last Percentage calculations are performed
arithmetic function key depressed
is ai-
easily with
the 24K calculator. For ex-
ways saved as the constant (addend, ample,
to calculate 1.5% monthly charge
subtrahend, multiplier,
or divisor). The on a
department store account balance of
constant function is the last arithmetic $340.00. make
the following entries:
function key depressed before depressing Keyboard Entry Display
the G key. To perform multiple 340 340.
operations with
the saved constant, enter
. 0 1.5 1.5
Repeat Operations a new augend, minuend, multiplicand or
the working register_
!.ill 5.1
The repeat operation capability
of your I dividend, and depress
the B key for
Basic Calculations Rockwell 24K
is a convenient feature that
As another example, suppose you have 1
an answer.
Your Rockwell 24K ·performs arithmetic enables
you to add, SUbtract, multiply or
answered 57 of 65 examination questions
For example,
to increase a recipe which
calculations with algebraic logic. This divide a series
of identical numbers with- correctly. What
is your percentage of I
normally serves four people
to serve seven, correct answe
rs?
.6
7 8 9

Keyboard Entry Display
57 57.
[±] 65 65.
~ 87.6923
When used with the IT] or El keys, the
~ key performs ADD-ON and DIS-
COUNT calculations automatically. This
capability
is another time-saving feature
when you want
to add or subtract a per-
centage ofe. number to that number.
To perform
an add-on or discount oper-
ation, enter the number which you want
to add on or discount, depress the GJ
key for add on or the B key for dis-
count, enter the
desired percentage, de-
press the ~ key to display the amount
of add-on or discount, and press the G
key to display the result.
Add-
on and discount operations can
be chaineo IT oesired. For example, it a (
$ 20.00 item is discounted hv 15% and a
6% sales tax is aooeo, wnal IS the total cost:
Keyboard Entry Display Comments
20.00 20.00
EJ
15
15.
~
3.
Discount
17.00 Discounted
ffi
6 6.
1.02
Sales tax
1=1 18.02 Total cost
~
Register Exchange
A useful feature
of your Rockwell 24K
calculator
is the register exchange c~pa
bility. Depressing the El key exchanges .
the number in the display
with the
number in the working register (the pre-
viously jisplayed number). One example
of the convemence of this feature is i 1-
lustrated bythe following division problem
involving acomplex denominator.
Problem: 15 = 1.6666666
3+6
Keyboard Display
Entry Register Working Register
3 3. Undetermined
[±] 3. 3.
6 6. 3.
[±] 9. 6.
15 15. 9.
~ 1.666666~ 1~:
MEMORY OPERATIONS
Your Rockwell 24K memory lets you
store
or accumulate numbers in the memo
ory without affecting, or being affected
by, arithmetic operations. This feature
permits you
to solve complex problems
without writing down intermediate an-
swers. Problem:
(5x7.5) + (27';'-4.5) = 43.5
4. Depressin~ the ICE/CI key during an I
Entry Display Memory
Keyboard overflow
(see Overflow Conditions)
cancels the overflow condition. Chain ,
5
5.
O.
and constant operations are not affect- .
[R]
5.
O.
ed by overflowing.
7.5 7.5
O.
37.5
O.
~
37.5 37.5 MemQry I OVERFLOW CONDITIONS
Indicator ' The following operations ' result in
an
"ON"
overflowcondition which causes the Over-
27 27. 37.5
flow Indicator, all deci1mal Pfints, to light
ffi
27.
37.5
end all keys except CE/C to become
4.5 4.5 37.5 inoperative:
~
6. 37.5
6.0 43.5
1. Any answer or 'subtotal exceeding 8
.43.5 43.5 whole digits
to the left of the deci-
llii1BJ
mal point, regardless of the arithmetic
sign (absolute value greater than
CLEAR OPERATIONS I
1. A single depression of the \CE/C \ key 99,999,999).
The 8 most significant
following a number entry
clears the digits
are displayed as follows:
displayed number
but does not affect I
@.X.X.X.X.X.X . I . You may
:he stored constants or the operation
proceed with the problem solution
In progress.
after depressing the \CE/C I key once
2. If there is no overflow condition a
to clear the overflow condition, but
single depression
of the \CE/C I key you must
multiply the final problem
after
an arithmetic function key or
answer by 108 (100,000,000)
or move
answer key clears the calculator (ex- the decimal
point 8 places to the
cept the memory). right. Any numbers subsequently
added or sub~racted must be divided
key clears any operation in. progress
3. A double depression of the [CEtC ] by 108 before entering.
If two
and clears the calculator (except the overflows occur in the
same prob-
memory). lem. the final
answer must be multi-

plied by 108 X 108 =10
16
and so on.
A memory accumulation exceeding 8
whole digits to the left of the decimal
point, regardless of the arithmetic sign,
The number
to be added to the mem-
ory remains in the display with lead-
in zeroes sufficient
to fill the display:
O.O.O.O.O.X.X:X: . The number
in ,the memory
is unaffected. Depress-
ing the ICE/CI key clears the overflow
condition
and the number remains in
the display.
r= XXX. I
Division by zero. All zeroes and
decimal points are dijlayed:
l. o.o.o.O.O.O.O,Q. .
14
FULL ONE YEAR WARRANTY
(U.S.A. and Canada)
The following warranty has been drafted to com- Out-of-Warranty Service
ply with the new Federal law applicable to pro-
If the calculator feils to operate satisfactorily
ducts manufactured after July 4,
1975 , beyond the one-year warranty period, Rockwell;
Rockwell Intemational Corporation warrants this Customer Service Cen1ers will repair
and return the
electronIc calculator and accessorIes (excluding calculator
to you at our prevailing service rates.
any non rechargeabla battery) against defects
In ROCKWELL CUSTOMER
materials and workmanship and operating malfunc- SERVICE CENTERS
tions for a period of one year .from the date of United States and Canada
retail purc~ase. This warranty IS for the benefit Rockwell Intemational Western Service Center
of the orlgonal retail purchaser and any subsequent P.O. Drawer
5077
transferee during the warranty.perlod. 1 9500e
g
Ui
gne Drive
In case of a defect. malfunctIOn, or other failure Sunnyvale, California 94088
to conform to the above walTsnty. Rockwell will,
at Its option, rapalr or replace the calculator WAR RANTY OUTSIDE
without charge within a reasonable tlma after its USA AND CANADA
receipt by our service center. The tlme'requlred For warran1y out:ide of USA and Canada see the
for rspalrs will be added to the warranty period. enclosed warranty card, or ask your distributor!
For service
under this warranty, simply retum the dealer for warranty Information.
calculator prepaid within the warranty. period
to Service Available Outside USA and Canada
the naarest Rockwell Customer Service Center British Isles
listed below .. You must also Include a copy of !Sumlock Anit a, Ltd. Service Canters are located
the sales
reea'pt or othar proof of purchase date. throughout the BritiSh Isles. Canso It your local
Calculators returned
without proof of purchese telephone directory for your nearest center.
date will be S9rviced
out of warranty at our prevail- '
Ing Service rates. France and Germany
Exclusions and
limitations Rockwall- HWT, S.A. Rockweil Intarnational,
This warranty does
not extend to any damage or Pctris, France G.m.b. H.
malfunction I"l'sulting from misuse. nagleet or acci- Frankfurt, Germany,
dent.
Tha' remedies described above are the ax-
Other Countries
elusive remedies under this warranty
or any implied I Contact your dealer or distributor.
warranty.
and IN NO EVENT SHALL ROCKWELL
BE LIABLE FOR CONSEQUENTIAL DAMAGES. 2520·D·116NEW 10·75
1226 R02·Q01
15
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