TI-65 Programs Part I:
Digital Root, Complex Number Multiplication, Dew Point
Recently working with the HP-71B and Radio Shack EC-4004, I
am feeling the 1980s vibes and staying in the decade for the 1987 classic
calculator Texas Instruments TI-65.
Some background information of the TI-65 (provided by
Datamath): http://www.datamath.org/Sci/Galaxy/TI-65.htm
Did you know the TI-65 has a timer? Click here to see a video demonstration!
This is the first part of programs for the TI-65 for this
Fourth of July.
Click here for Part II: Reynold’s Number/Hydraulic Diameter, Escape Velocity, Speed of Sound/Resonant Frequencies in an Open Pipe
Click here for Part II: Reynold’s Number/Hydraulic Diameter, Escape Velocity, Speed of Sound/Resonant Frequencies in an Open Pipe
Click here for Part III: Impedance and Phase Angle of a Series RLC Circuit, 2 x 2 Linear System Solution, Prime Factorization
TI-65 Digital Root
Takes the digital root of an integer. To find the digital root:
1. Add up the number’s
digits.
2. The sum is over
10, add the digits again.
3. Repeat step 2
until you get a single digit.
Or alternatively, use the formula dr(n) = 1 + ((n-1) mod 9)
= n – 9 * intger((n-1)/9)
Program:
CODE
|
STEP
|
KEY
|
12.0
|
00
|
STO 0
|
49
|
01
|
-
|
9
|
02
|
9
|
38
|
03
|
*
|
16
|
04
|
(
|
16
|
05
|
(
|
13.0
|
06
|
RCL 0
|
49
|
07
|
-
|
1
|
08
|
1
|
17
|
09
|
)
|
28
|
10
|
÷
|
9
|
11
|
9
|
17
|
12
|
)
|
2nd 27
|
13
|
ITNG
|
14
|
14
|
=
|
51
|
15
|
R/S
|
Input: Enter integer,
press [RST] [R/S]
Test 1: dr(1555) = 7
Test 2: dr(38267) = 8
TI-65 Complex Multiplication
(a + bi)*(c + di) = (r1*r2) * e^(i*(θ1 + θ2))
Where r1 ∠ θ1 is the polar form of a + bi
and r2 ∠
θ2 is the polar form of c + di.
Program:
CODE
|
STEP
|
KEY
|
COMMENT
|
44
|
00
|
X<>Y
|
Start with a
|
51
|
01
|
R/S
|
Prompt for b
|
-2nd 22
|
02
|
INV 2nd
P-R
|
Convert to Polar
|
12.1
|
03
|
STO 1
|
|
44
|
04
|
X<>Y
|
|
12.0
|
05
|
STO 0
|
|
51
|
06
|
R/S
|
Prompt for c
|
44
|
07
|
X<>Y
|
|
51
|
08
|
R/S
|
Prompt for d
|
-2nd 22
|
09
|
INV 2nd
P-R
|
Convert to Polar
|
12.59
|
10
|
STO+
|
|
1
|
11
|
1
|
STO+ 1
|
44
|
12
|
X<>Y
|
|
12.38
|
13
|
STO*
|
|
0
|
14
|
0
|
STO* 0
|
13.0
|
15
|
RCL 0
|
|
44
|
16
|
X<>Y
|
|
13.1
|
17
|
RCL 1
|
|
2nd 22
|
18
|
2nd P-R
|
Convert to
Rectangular
|
51
|
19
|
R/S
|
Display imaginary
part of product
|
44
|
20
|
X<>Y
|
|
51
|
21
|
R/S
|
Display real part
of product
|
(a + bi)*(c + di) = x + yi
Input: a [RST] [R/S],
b [R/S], c [R/S], d [R/S]
Output: y [R/S], x
Test 1: (5-3i)*(4+i):
5 [RST] [R/S]. -3 [R/S], 4 [R/S], 1 [R/S]
Result: -7 [R/S]
23, 23-7i
Test 2: (-6+3i)*(2 +
2i)
Result: -18 – 6i
TI-65 Dew Point Calculation
This program accepts input and displays dew point in degrees
Fahrenheit (°F).
Source for
formula: http://ag.arizona.edu/azmet/dewpoint.html
CODE
|
STEP
|
KEY
|
COMMENT
|
3rd 28
|
00
|
3rd °F-°C
|
Convert to °C
|
12.0
|
01
|
STO 0
|
|
38
|
02
|
*
|
|
1
|
03
|
1
|
|
7
|
04
|
7
|
|
57
|
05
|
.
|
Decimal Point
|
2
|
06
|
2
|
|
7
|
07
|
7
|
|
12.1
|
08
|
STO 1
|
|
28
|
09
|
÷
|
|
16
|
10
|
(
|
|
2
|
11
|
2
|
|
3
|
12
|
3
|
|
7
|
13
|
7
|
|
57
|
14
|
.
|
Decimal Point
|
3
|
15
|
3
|
|
12.2
|
16
|
STO 2
|
|
59
|
17
|
+
|
|
13.0
|
18
|
RCL 0
|
|
17
|
19
|
)
|
|
59
|
20
|
+
|
|
51
|
21
|
R/S
|
Prompt for h
|
32
|
22
|
LN
|
|
39
|
23
|
=
|
|
28
|
24
|
÷
|
|
13.1
|
25
|
RCL 1
|
|
39
|
26
|
=
|
|
12.1
|
27
|
STO 1
|
|
38
|
28
|
*
|
|
13.2
|
29
|
RCL 2
|
|
28
|
30
|
÷
|
|
16
|
31
|
(
|
|
1
|
32
|
1
|
|
49
|
33
|
-
|
|
13.1
|
34
|
RCL 1
|
|
17
|
35
|
)
|
|
39
|
36
|
=
|
|
-3rd 28
|
37
|
INV 3rd °F-°C
|
Convert to °F
|
51
|
38
|
R/S
|
Input: Enter temperature in °F [RST] [R/S], enter
humidity (as a decimal) [R/S]
Output: Dew Point in °F
Test 1: temperature =
68°F, humidity = 0.5 (50%)
68 [RST] [R/S], 0.5 [R/S]
Result: dew point ≈
48.68533155°F
Temp 2: temperature =
93°F, humidity = 0.35
Result: dew point ≈
61.29167421°F
Happy Birthday United States!
This blog is property of Edward Shore, 2016.
