Texas Instruments TI-5015 User manual

TABLE OF CONTENTS
Page
INTRODUCTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
Features . . . .. . . .. . .. . . . .. .. . .. . . .. . . .. . .. . . .. . .. . . . .. . . .. . . . . 1
Electronic Printer Operation . .. . . .. . . .. . .. . .. . . .. . .. . . . . .. . . .. . . 2
BASIC OPERATIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
Initial Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
Addition and Subtraction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
Error/Overflow Conditions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
Multiplication and Division . . .. . . . .. . .. . .. . .. . . .. . .. . . . . .. . . .. . . 8
Mixed Calculations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
11
Operations with Grand Total Register ............................ 13
SPECIAL FUNCTIONS ............................................ 15
Add Mode Calculations ....................................... 15
Fixed Point Calculations ....................................... 16
Multiplication and Division by a Constant ......................... 17
Percent Calculations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
SERVICE INFORMATION . . . . . . .
.................................. 23
Printing Paper Replacement . .. . . .. . .. . .. . . . .. . .. . . .. . . .. . . .. . . 23
Printhead Cleaning . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26
In Case of Difficulty ............................................ 27
Calculator Exchange Centers . . .. . .. . .. . . .. . . .. . .. . . . .. . . .. . . . . 27
If
You Need Service Information ................................ 28
APPENDIX
Conversion Factors
............................. Inside Back Cover
USE ONLY TEXAS INSTRUMENTS TP-20225 OR TP-27225 THERMAL
PRINTING PAPER. OTHER PAPER MAY DAMAGE CALCULATOR AND
VOID WARRANTY.
IMPORTANT: Dim or partial printing may be remedied with the PRINTHEAD
CLEANING procedure on page 26 of manual.
IMPORTANT
Record the serial number from the bottom of the
calculator and purchase date in the space below. The
serial number is identified by the words "SERIAL NO."
on the bottom case. Always reference this information in
any correspondence.
Tl-5015
Model No. Serial No. Purchase Date
Copyright@ 1977, Texas Instruments Incorporated

INTRODUCTION
This electronic desk-top printing calculator provides a high degree of
versatility and performance. Its unique construction is made possible by the
whisper-quiet, electronic printer (no ribbon) and reliable integrated circuits
pioneered by Texas instruments. The convenience of the calculator is
accented by its easy-to-use keyboard, independent add register, grand total
register and many other features. Like all other products manufactured by
Texas Instruments, this calculator has been designed and built to provide
you with years of dependable service.
FEATURES
independent Add Register -Addition and subtraction with the familiar
entry sequence of standard business machines. Perform multiplication and
division without affecting previous add/subtract entries.
Grand Total Register -Automatically accumulates totals from the add
register. When the Grand Total is printed, this register is cleared and the
grand total
is placed in the entry register for further calculations. Serves as
an accumulator for add/subtract totals.
Light Weight- Weighs less than 2V2 pounds for convenient operation at
work or at home.
Electronic Printer -Quiet, smooth-running electronic printer developed by
Texas Instruments prints up to
10 digits plus audit trail.
Repeat
Entry -Once a number has been keyed into the calculator, it can
be entered as many times as you need by sequentially pressing an
operation key (
+, --).
Add Mode-For easy entry of dollars and cents, select add mode for
automatic decimal positioning at two places or select floating point for
maximum accuracy.
Fixed
Point Operation - A fixed decimal point (from 1to 9 decimal places)
is selectable via keyboard entry.
Non-Add Operation -Prints reference numbers without affecting
calculations.
Percent Key- Permits easy calculation of percentages for add-on, taxes,
discounts and other problems.
Automatic Constant -Multiplication and division by a constant number
without reentering numbers.
Keyboard Buffering -Enter additional numbers and functions while
calculator
is still printing.
Two-Key Roll-Over-Lets you press a second key even before the
previously pressed key is released.

ELECTRONIC PRINTER OPERATION
The paper used by the electronic printer is a heat-sensitive (thermal) paper
(Texas Instruments TP-20225 or TP-27225). The only mechanical part of the
printer is a precision stepper motor which advances the paper past the
electronic printhead that is stationary. When printing, small semiconductor
(solid-state) elements are heated very quickly by electronic circuits and
produce color spots on the thermal paper. These spots form the numbers
and symbols you can read on the thermal paper.
Since the printer is basically an electronic device, it does
not require special
ink ribbons or special maintenance. Using metal probes, sharp objects or
lubricants may damage the printhead or rubber roller. Please refer to
Service Information section of this manual for paper replacement
instructions and actions to take if a difficulty occurs.
NOTICE
THE PRINTING ON THERMAL PAPER MAY FADE IF
EXPOSED TO LIGHT OR HIGH TEMPERATURES FOR
LONG PERIODS OF TIME. FOR PERMANENT
STORAGE,
Al 'NAYS FILE PRINTED TAPES AWAY
FROM LIGHT AND
HEAT.
2

BASIC OPERATIONS
This desk-top printing calculator is quite simple to operate. You have
probably already used most of the functions successfully. However, there
are many valuable features of the calculator which are not obvious when
looking at the keyboard. The following descriptions and examples will assist
you in learning the detailed operation of your calculator.
INITIAL OPERATION
The calculator should be connected to 115 Vac/60Hz electrical outlet before
operating.
The power switch is located on the right side of the calculator. Push the
switch toward the rear ofthe calculator to apply power. Each time the power
switch is turned on, the calculator prints 0.T to indicate it iscleared and
ready for operation.
A paper advance
key[]] allows you to run out extra paperto create space
between problems orfor tearing off the paper after completing a problem.
ADDITION AND SUBTRACTION
Numbers are keyed into the calculator in the same left-to-right sequence
that you read them. Addition and subtraction entries are made with the same
rapid-entry style as most standard business machines. A unique feature of
the calculator is that addition and subtraction entries are kept separate from
multiplication and division entries within the calculator. This feature is
made possible
by the independent add register. The grand total register
accumulates totals from the add register and serves as a memoryfor add
register totals. Detailed examples ofthese features are shown in Mixed
Calculations.
The following keys are used to perform simple addition and subtraction:
Add Key[±] -Adds the last entered number orthe last printed result to the
independent add register. A
"+" symbol is printed tothe right of the number
added.
Subtract Key G - Subtracts the last entered number orthe last printed
result from the independent add register. A "- " symbol is printed
to the right
ofthe number subtracted.
Non-add/Subtotal Key M - When used immediatelyfollowing a number
entry, the entered number is printed with
the"#" symbol printed to the left of
the number. These numbers are for labeling only and are not entered into
the independent add register orthe grand total register and
do not affectthe
calculation in progress. When the key is used immediatelyfollowing a
function
key, the present subtotal of the independent add register is printed
with an
"S" symbol printed tothe right of this subtotal. The contents of the
independent add register and grand total register are not affected
by the
Mkey.
3

Total or Grand Total Key ~ - A single press of this key prints the total of
the independent add register with the "T" symbol printed to the right ofthe
total. This total is also placed
in the entry register and the grand total
register. The
~ key also clears the independent add register so that the
calculator is ready for new addition and subtraction entries. A second
consecutive press ofthe
~key prints the accumulated sum of all totals
from the independent add register with a "G" symbol on the right, clears the
grand total register and places the.grand total (GT)
in the entry register for
further use if needed. The GT register accumulates totals from the
independent add register only when
the~ key is pressed. (See
Operations with Grand Total Register for example.
Clear/Clear-Entry
Key~ -When used immediately following a number
entry, this key will clear the entered number and allow another number to be
entered
in its place without affecting the independent add register or the
grand total register. Note thatthis key will not clear the independent add
register or the grand total register. Pressing
~once, automatically clears
the independent add register afterthe total is printed.
Pressing~ a second
time will cause the contents of the grand total (GT) register to be printed and
the GT register to be cleared. See Multiplication
and Division for further
explanation of the
~ key.
The decimal point key is used wherever itappears in a number. When the
decimal is not entered, the calculator automatically prints the decimal point
to the right ofthe last number entered
when[±] orG is pressed.
Example: 5.67 + 6 = 11.67
Enter Press Print
O.T Set power switch to ON
5.67
[±] 5.67+
6
[±] 6.+
~ 11.67T
After
the~ key is used, a new problem can be entered without manually
clearing the independent add register.
When a total is negative, a minus sign appears to the left ofthe total.
Example:
-8 + 3.21 -4.6 = -9.39
Enter Press
a G
3.21
4.6
4
Print
8.-
3.21+
4.6-
-9.39T

The repeat add/subtract feature ofthe calculator allows you to repetitively
add or subtract the same number withoutreentering the number.
Example: 4.59 + 4.59 + 4.59 - 6 - 6 =
1. 77
Enter Press
4.59 [:±]
[:±]
[:±]
6 G
G
Print
4.59+
4.59+
4.59+
6.-
6.-
ill@ 1.77T
A subtotal is desirable when you wish to obtain intermediate and final
results.
Example: 1.064 -.018 = 1.046
1.064 -.018 + 1.19 = 2.236
Enter
1.064
.018
1.19
Press
[:±]
G
M
[:±]
ill@
Print
1.064+
0.018-
1.0468
1.19+
2.236T
When used immediatelyfollowing a number entry, the M key will cause the
number
tQ.be printed without affecting the calculation.
Example: A listing shows a certain rating number for six different items. Find
the total rating of item number
1, 4 and 6.
Item No. Rating No. Item No. Rating
No.
1 17 4 76
2 8.5 5 14.5
3 45 6 34
Enter Press Print
1 M
#1.
17 [:±]
17.+
4 M
#4.
76 [:±]
76+
6 M #6.
34 [:±]
34.+
ill@ 127.T
5

Occasionally, you may catch yourself entering an incorrect number oreven
decide the numberyou keyed
in is not wanted. When this happens, the~
key can be used to clear the unwanted entry.
Example: 49.01 + 16.55 + 4.9 = 70.46
Enter Press Print Comments
49.01 rn 49.01+
16.555
~
Remove incorrect entry
16.55 rn 16.55+ Enter correct value
4.9 rn 4.9+
~
70.46T Total
Unwanted entries can also be effectively eliminated from the total value after
theITJ orG operation by simply using the opposite operation to cancel
the effect ofthe unwanted entry.
Example: 49.01 + 16.55 + 4.9 = 70.46
Enter Press Print Comments
49.01 rn 49.01+
16.555 rn 16.555+ Faultyvalue entered
G
16.555- Faultyvalue removed
16.55 rn 16.55+ Correctvalue entered
4.9 rn 4.9+
~
70.46T
Total
If you accidentally use~ when you intended to useM, the total is easily
reentered intothe independent add register with
the[±] key. However,
remember that each total
"T" is summed to the grand total register.
Example: 156 + 65 + 320 =
541
Enter Press Print
156 rn 156.+
65 rn
65.+
~
221.T
rn 221.+
320 rn 320.+
~
541.T
If you frequently perform calculations involving dollars and cents, you may
wish to use the convenient add mode feature of the calculator described
later
in this manual.
6

ERROR/OVERFLOW CONDITIONS
You can enter up to 10 digits into the calculator. If you enter 11 or more
digits,
an entry overflow occurs which causes the calculator to clear the first
11 digits entered and print ERROR. However, if the 12th, 13th, etc., digits
have been entered, they are accepted as part of the new entry. When this
occurs, press 1™and you can reenter a number that has 10 or less digits
without affecting previous entries.
Example: 123456.7899 + 555765.4321 = 679222.222
Enter Press Print Comments
123456.7899 rn 123456.7899+
5555765.4321 ERROR
11 digits entered
1 ™ Clear for new value
555765.4321 rn 555765.4321+ Correct value entered
[!fill 679222.222T Total
A register overflowwill also cause ERROR to be printed. If the accumulated
contents ofthe add registers are larger than 9999999999
(1 Odigits) or
-999999999 (9 digits for negative results), ERROR Tis printed and the
contents of that register are automatically cleared.
Example: 9,999,999,999 + 1 = Overflow
Enter
9999999999
1
Press
rn
rn
Print
9999999999.+
1.+
ERRORT
If grand total overflow occurs, the calculator prints ERROR G, skips a line
and clears the grand total register. The independent add register and entry
register are also cleared for a new problem to be entered.
Enter Press Print
3333333333 rn 3333333333.+
[!fill 3333333333.T
4444444444 rn 4444444444.+
[!fill 4444444444.T
5555555555 rn 5555555555.+
[!fill 5555555555.T
ERRORG
The calculator uses 5/4 round off for 10-digitpositive or 9-digit negative
results. This means that an internal result of
-999999999.4 will round off to
-999999999. However, -999999999.5 will round upcausing an overflow. In
addition, the round off operation occurs with each entry. If thevalue 0.4 is
added to 5555555555, the internal result is rounded off immediately to
5555555555 again as if the 0.4 were never entered.
7

MULTIPLICATION AND DIVISION
Now that you are familiar with the addition and subtraction keys on the
keyboard, the multiplication and division at the top of the keyboard will be
described.
Keep in mind that multiplication and division operations are independent of
addition and subtraction. The summing of a column of numbers can be in
progressand
an intermediate calculation involving 00, e±::I and[§] can be
performed without affecting the summing operation. See Mixed Calculations
for further explanation and examples.
The four basic keys concerned with multiplication and division are:
Multiply Key 00 -Causes the last entered number or last printed result to
be printed
as the multiplicand with a "x" symbol printed to the right of the
number.
Divide Key e±::I -Causes the last entered number orthe last printed result
to be printed
as the dividend with a"+" symbol printed to the right of the
number. Division by zero is invalid and will cause ERROR to be printed.
Equals Key[~ -Completes multiplication or division. When used
following multiplication or division, the last entered or printed number is
printed as the multiplier or divisor with an
"=" symbol printed to the right of
the number. Then the result is printed with no symbol tothe right.
Clear/Clear-Entry Key @lg~ -When used immediately following a number
entry, this key will clear the entered number and allow another number to be
entered in its place without affecting previous entries. When used following a
00 or G:J entry, or pressed twice after a number entry, a "C" symbol is
printed to indicate that the multiplication or division problem has been
cleared and the calculator is ready for entry of a new problem. In mixed
calculations, this key will not clear the independent add register or grand
total register.
Multiplication and division problems are quite simple to solve since most
problems maybe entered in the same order they are written.
Example: 24.3 x 15 = 364.5
Enter Press
24.3 00
15
Example: 130 ..,._ 6.5 = 20
Enter
130
6.5
[§]
Print
24.3x
15.=
364.5
Print
130-;-
6.5=
20.
Notice that it is not necessary to press
[CZ"~ after a problem before starting a
new problem when
the[§] key is used.
8

Example: 120 x 50 30 = 200
Enter
120
50
30
Press
[)<]
r:±J
8
Print
120.x
50.+
30.=
200.
The result of one problem can easily be picked up as
an entry to another
problem without entering the result.
Example: 120 x
50 = 6000 6000 + 30 = 200
Enter
Press Print
120 [K)
120.x
50
[:=_]
50.=
6000.
C:+:J
6000.+
30
8 30.=
200.
When
an erroneous number entry is made, the ~El key may be used to clear
that entry in the same manner shown for addition and subtraction.
Example: 16 + 5 x 32 = 102.4
Enter Press Print
16 G:J 16.+
6 [§]
5 00
32 8
5.x
32.=
102.4
Comments
Remove incorrect entry
Enter correct value
The
@zc:EJ key will also act as a clear key for multiplication and division
problems. If at some point
in a problem you decide to reenter the problem or
even start a new problem, simply
press[§] once (or twice after a number
entry) and the calculator will print a
"C" symbol indicating it is ready to start a
new problem. The
[§] key does not affect the contents ofthe independent
add register or grand total register used for addition and subtraction.
Example: 5.9 x 13.6
+(start new problem)
39 + 12.5 = 3.12
Enter Press\
5.9 [K)
13.6 [±]
39
12.5
[C2_Ci]
[±]
8
9
Print
5.9.x
13.6+
c
39.+
12.5=
3.12

If you decide to start a new problem immediately after a number entry, the
[Slci] key must be pressed twice. The first ~2cEI clears the number entry only
and a second
rz.;:•1 clears the pending calculation.
Example: 5.9 13.6 (start new problem)
39-;- 12.5 = 3.12
Enter Press Print
5.9 [xJ
5.9x
13.6 [t;C:~
@Z"_CEj
c
39
li=J
39.7
12.5
[=:J
12.5=
3.12
Comments
Clears number 13.6
Clears pending 5.9x
New problem total
Another method to terminate a multiplication or division problem is to press
[~ and begin the new problem. While this method is simple, if the printed
paper tape is saved for reference purposes, there is
no clear indication that
the problem was not completely entered.
Negative numbers cannot be directly keyed into the calculator in
multiplication and division problems. A number can be assigned a negative
value as
an entry to or result of the independent add register. A negative
number can contain as many
as 9 digits before overflow will occur.
Example: 11.32 x
(-6) x (-5.04) = 342.3168
Enter Press Print Comments
11.32
[5<1
11.32x 1st Multiplier
6 G 6.-
[Itc;TJ -6.T
00
-6.x
2nd Multiplier
5.04 G 5.04-
[r@
-5.04T
[.§:] -5.04=
3rd Multiplier
342.3168
10

Decimal fraction results (results with digits to the right of the decimal point)
that exceed
10 digits are automatically rounded up one if the 11th digit is 5 or
larger. Negative results are rounded to 9 digits in the same manner.
Example: 5 + 3 = 1.6666666666......
Enter
5
3
Press
[±]
§
Print
5.+
3.=
1. 666666667
An entered number or printed result can easily be squared without
reentering the number.
Example: 125 x 125 = 15625
Enter
125 Press
00
§
Print
125.x
125.=
15625.
Multiplication and division overflow conditions are similarto the addition and
subtraction overflow conditions in that more than 10 digits in an intermediate
or final result will cause ERROR to be printed and the calculator to be
automatically reset for entry of a new problem. An entry overflow will also
cause ERROR to be printed and the sequence
[I] ™should be used to
continue without affecting previous entries. As in addition and subtraction, a
negative result cannot be largerthan
-999999999. (9 digits).
MIXED CALCULATIONS
The previous descriptions have not considered problems that require a
combination of addition, subtraction, multiplication and division. Besides the
differences in entry methods, it is very importantto remember that the
calculator internally keeps the results of multiplication and division entries
separate from addition and subtraction entries as ifthere are two calculators
in one. The first example illustrates an addition and a multiplication problem
which uses the same numbers without a number being entered twice. Notice
that the calculator provides two results as iftwo different problems were
entered separately.
Examples: 12 + 15 = 27, 12 x 15 = 180
Enter
12
15
Press
rn
00
rn
§
Print
12.+
12.x
15.+
15.=
180.
27.T
11
Comments
1st Add entry
1stMultiply entry
2nd Add entry
2nd Multiply entry
Multiplication result
Addition result

The value of the independent operations can be realized when you begin
solving mixed or complex calculations. Many of the following examples
would require a memoryto store intermediate results if the calculator did not
have this independent processing capability.
Sum of Products
Example: 4 x 11.99 = 47.96
6 x 2.97 = 17.82
12x 0.98= 11.76
Total 77.54
Enter Press
4
CKJ
11.99
@]
IT]
6
CKJ
2.97
@]
IT]
12
CKJ
.98
@]
Sum of Quotients
Example: 1.98_4.98= -0.1275
4 8
Enter Press
1.98
[±]
4
@]
IT]
4.98
[±]
8
@]
G
~
12
Print
4.x
11.99=
47.96
47.96+
6.x
2.97=
17.82
17.82+
12.x
0.98=
11.76
11.76+
77.54T
Print
1.98+
4.=
0.495
0.495+
4.98+
8.=
0.6225
0.6225-
-0.1275T

Product of Sums
Example: (2 + 3) x (4 + 5) = 45
Enter
Press
2 [±]
3 [±]
[!ili]
00
4 [±]
5
[±]
[!ili]
@]
Product/Quotient of Sums
Example: <
7 + 5) x < 6 -4) +
-2.66666667
3-12
Enter Press
7
[±]
5
[±]
[!ili]
00
6
[±]
4 G
[!ili]
[±]
3 [±]
12
G
[!ili]
@]
Print
2.+
3.+
5.T
5.x
4.+
5.+
9.T
9.=
45.
Print
7.+
5.+
12.T
12.x
6.+
4.-
2.T
2.+
3.+
12.-
-9.T
-9.=
-2.66666667
OPERATIONS WITH GRAND TOTAL REGISTER
The independent add register allows you to perform mixed calculations as·
discussed
in the preceding section. The grand total (GT) register serves as a
memory for add/subtract totals. A single press ofthe[!ili] key causes the
calculator to print the total of all add/subtract entries with a ''T" symbol
printed to the right ofthe total and places this total
in the GT register. A
second consecutive press of the [!ili]key prints the accumulated sum of all
totals from the independent add register. The symbol "G" is printed to the
right of this grand total and it is placed
in the entry register for possible further
calculations. Athird press prints
O.T.
Remember to press[!ili] until "G" is printed before starting a problem set
using the grand total register.
13

Example: 12.3 + 4.56 = 16.86
21.34 + 17.1+0.12+1.234-~ 39.794
12.34 + 12.34 + 12.34 + 12.34 ~ 49.36
Enter
12.3
4.56
21.34
17.1
.12
1.234
12.34
Grand Total = 106.014
Press
@GT I
[!m] *
[!lQ!] *
[.±]
[]]
[r"illJ
[+]
["f J
[~]
[±]
[!!"0]
[±]
[±]
[+_]
CTI
@i;r]
[TiG!J
Print
112.3725G
O.T
O.G
12.3+
4.56+
16.86T
21.34+
17.1+
0.12+
1.234+
39.794T
12.34+
12.34+
12.34+
12.34+
49.36T
106.0i4G
Comments
Previous grand total
Add register cleared
Grand total cleared
Simple addition
First total
Second total
Third total
Grand total
*Additional key entries for illustration only, calculator is ready for new
add/subtract grand total problems when
"G" is printed.
The
[i'!_~T] key allows you to find the grand total of all add/subtract entries after
you have completed a series of mixed calculations. When you finally press
the
[TJGrJ key twice, the calculator prints the grand total of all totals from the
independent add register. Only two simple facts must be kept in mind to
implement mixed calculations:
1) The add register
is affected only by the[+ J, l=], and [i!]I] function
keys. (Pressing the
[_T1Gi! key clears the add register to zero.)
2) The contents of the add register are always available as an entry after
a subtotal or total operation by simply pressing one of the function
keys[+ J, - [)(], or[±:].
For example, if you key in the previous example problems entitled Sum of
Products and Sum of Quotients exactly as shown, then press [f1Gr!, the
total of both problems will be printed: 77.54 + (-0.1275) = 77A125G.
14

SPECIAL FUNCTIONS
ADD MODE CALCULATIONS
All operations up to this point have been in the floating mode where the
decimal point "floats" to its proper position. The add mode feature of the
calculator rounds all entries to two decimal places. It is convenient when
calculations involve dollars and cents.
Floating/Add Mode Key
[@-Each use of this key alternately selects the
add mode and floating mode. The calculator is in the floating mode when the
power switch is turned on and pressing the
[@ key one time selects add
mode. Pressing
[@ again, returns the calculator to the floating mode.
In the add mode, number entries followed by[±] ,G ,are automatically
entered with the decimal point positioned two places to the left of the last
digit of each number entry. Therefore, dollars and cents may be entered
without using the decimal point
key.
Example: $5.23 + $17.00 -$0.75 = $21.48
Enter Press Print
[@
523 [±] 5.23+
1700 [±]
17.00+
75
G
0.75-
[fil!] 21.48T
If you do not know which mode has been selected, press [fil!]. If O.OOT is
printed, the calculator is in the add mode. If
O.T is printed, the calculator is in
the floating (normal) mode.
The decimal point key may be used to override the add mode for individual
entries. Ifmore than two digits are entered after the decimal point entry, the
number is rounded to two decimal places when summed or subtracted. ·
Example: $3.133 + $0.005 + $4.56 = $7.698 = $7.70
Enter Press Print Comments
[fil!] 21.48G Previous grand total
[fil!]
O.OOT
Checkfor add mode
3.133
[±]
3.13+ 3.133 truncated to 3.13
.005
[±]
0.01+ .005 rounded to
.01
456 [±]
4.56+ Normal entry
[fil!] 7.70T Add mode total
15

Multiplication and division entries are not affected by add mode, but results
are always rounded to two decimal places.
Example: 1.556 x 3.21 + 56.113 = .0890125283 = .09
Enter Press Print
ill@ 7.70G
ill@ 0.00T
1.556
00
1.556x
3.21 [±] 3.21+
56.113
@]
56.113=
0.09
FIXED POINT CALCULATIONS
Another feature ofthe [fZfil key allows you to select any number of decimal
places (from Oto 9) to print when working a problem. Pressing the following
sequence of keys puts the calculator in the Selected Decimal Mode, where
"N" is the desired number of decimal places:
[fZfil -+ N -+ ill@
To return to floating mode simply press[fZfil, just as you would to change
from the add mode to floating mode. The following is an example of various
calculations in the selected decimal mode.
Enter Press Print
[fZfil
1 ill@ 0.0
5 rn
5.0+
12 rn
12.0+
ill@ 17.0T
00
17.X
2
[±]
2.+
3
@]
3.=
11.3
13.25 rn 13.3+
[±]
13.3+
5
@]
5.=
2.7
[fZfil
1.15 rn 1.15+
ill@ 14.45T
16
Comments
Calculator powers up
in floating mode.
Fixed point 1
Total
The previous total
can be used for further
calculations by pressing
the desired function
key.
Rounded to 1decimal place
The number entered is
rounded to 1decimal place.
Rounded to 1decimal place.
Return to floating mode
Total

MULTIPLICATION AND DIVISION BY A CONSTANT
The calculator has an automatic constant register which will retain the last
00 or[±] entry and the composite multiplicand for multiplication orthe
divisor for division. The constant register has no effect
on normal
calculations as described thus far in the manual. Once the constant is
stored, the calculator is designed to lookfor the sequence of a number entry
followed by equals. When this sequence is used, the calculator uses the
number and function
in the constant register to complete the calculation.
The constant number is automatically replaced when a new problem is
entered or when
1§i1 is used to clear the problem (a "C" is printed).
For simple calculations, the first entry is the constant number in
multiplication and the second entry is the constant number in division.
Example: 5 x 3 = 15.5, 5 x 4 = 20, 5 x 0.95 = 4.75
Enter Press Print Comments
5 00 5. x 5 x stored as constant
3 El 3.=
15. 5 x 3 evaluated
4
El
4.=
20. 5 x 4 evaluated
.95
El
0.95=
4.75 5 x .95 evaluated
Example: 100 + 3 = 33.33333333, 18 + 3 =
6, 4.7 + 3 = 1.566666667
Enter Press Print Comments
100
[±]
100.+
3
El
3.=
+ 3 stored as constant
33.33333333 100 + 3 evaluated
18
El
18.=
6. 18 + 3 evaluated
4.7
El
4.7=
1.566666667
4. 7 + 3 evaluated
17

Since the divisor in division becomes the constant, the division constant can
be read directlyfrom the paper tape. However,
in multiplication the constant
number may actually be
an intermediate result that has not been printed.
The key sequence
[J] @] will cause the multiplication constant value to be
printed.
Example: Determine the constant value after solving the following problem.
36 x 4.5 + 12 x 6 =
81
Enter Press Print
36
00
36.x
4.5 [±]
4.5+
12
00
12.x
6 @]
6.=
81.
1
@] 1.=
13.5
The constantvalue is the composite result of the first three entries:
36 x 4.5 + 12 = 13.5.
The automatic constant allows
an entry or result to be divided into one (a
reciprocal) without reentering numbers. The key sequence to calculate the
reciprocal of
an entered number or the last printed result is[±] @] @].
Example: _1_ = 0.05
8+ 12
Enter Press
~
8 m
12 m
~
[±]
@]
@]
Print
O.T
8.+
12.+
20.T
20.+
20.=
1.
1.=
0.05
18
Comments
8 + 12 evaluated
+ 20 stored as constant
20 +
20 evaluated
1 +
20 evaluated