HP 15C: Stair Calculations
Variables:
Input:
R0 = Riser Height (RH)
R1 = Run
R2 = Rise
Store values in R0, R1, and R2 before running the
program.
Output:
R3 = number of stairs (S)
R4 = Treadwidth (TW)
R5 = Stringer Length (ST)
Formulas Used:
S = int(rise/RH) – 1
TW = run/S
ST = S * √(RH^2 + TW^2)
|
Step
|
Key
|
Key Code
|
|
001
|
LBL C
|
42, 21, 13
|
|
002
|
RCL 2
|
45, 2
|
|
003
|
RCL÷ 0
|
45, 10, 0
|
|
004
|
INT
|
43, 44
|
|
005
|
1
|
1
|
|
006
|
-
|
30
|
|
007
|
STO 3
|
44, 3
|
|
008
|
R/S (S)
|
31
|
|
009
|
1/X
|
37
|
|
010
|
RCL* 1
|
45, 20 ,1
|
|
011
|
STO 4
|
44, 4
|
|
012
|
R/S (TW)
|
31
|
|
013
|
X^2
|
43, 11
|
|
014
|
RCL 0
|
45, 0
|
|
015
|
X^2
|
43, 11
|
|
016
|
+
|
40
|
|
017
|
√
|
11
|
|
018
|
RCL* 3
|
45, 20, 3
|
|
019
|
STO 5
|
44, 5
|
|
020
|
RTN
|
43, 32
|
Example:
R0 = 7 inches (riser height)
R1 = 56 inches (run)
R2 = 80 inches (rise)
Results:
R3 = 10 (number of stairs)
R4 = 5.6 inches (treadwidth)
R5 ≈ 89.6437 inches (stringer)
This blog is property of Edward Shore. 2016
