*The Museum of HP Calculators*

#
Moon Landing Simulation for the 12C

This program is by Richard Beal and is used here by permission.

This program is supplied without representation or warranty of any kind.
Richard Beal and The Museum of HP Calculators therefore assume no responsibility
and shall have no liability, consequential or otherwise, of any kind arising
from the use of this program material or any part thereof.

##
Overview

This is adapted from the program in the library for the HP-25.
It needed quite a lot of changes because the tests x<0 and x<y do not exist on the HP-12C, so x<=y must be used instead.

An enhancement is that the remaining fuel is flashed on the display.

The existing documentation is otherwise correct except that in step 3 it should say just R/S not f PRGM R/S, and step 7 should be removed.

##
Listing

01 42 4 f 4 4 digit display
02 45 0 RCL 0
03 26 EEX
04 4 4
05 10 / Divide X by 10000
06 45 1 RCL 1
07 0 0
08 43 34 g x<=y If 0<=V?
09 43,33 14 g GTO 14 --> V positive or zero
10 33 R dn V negative
11 34 x<>y Add V and -X
12 30 -
13 43,33 16 g GTO 16 -->
14 33 R dn Add V and X
15 40 +
16 31 R/S Display V.X and get burn
17 45 2 RCL 2 Fuel
18 34 x<>y
19 43 34 g x<=y If Burn<=Fuel?
20 43,33 22 g GTO 22 --> Yes, so OK
21 43,33 42 g GTO 42 --> No, so prepare for crash
22 44,30 2 STO - 2 Subtract burn from fuel
23 5 5
24 30 -
25 44 3 STO 3 Acceleration is burn-5
26 2 2
27 10 /
28 45 0 RCL 0
29 40 +
30 45 1 RCL 1
31 40 +
32 44 0 STO 0 Altitude X=X+V+A/2
33 0 0
34 43 34 g x<=y If 0<=Altitude?
35 43,33 37 g GTO 37 --> Yes, so OK
36 43,33 53 g GTO 53 --> No, so crash
37 45 3 RCL 3
38 44,40 1 STO + 1 V=V+A
39 45 2 RCL 2 Display fuel remaining
40 43 31 g PSE
41 43,33 02 g GTO 02 --> Return to display V.X
42 45 1 RCL 1 Show crash
43 36 ENTER
44 20 *
45 45 0 RCL 0
46 1 1
47 0 0
48 20 *
49 40 +
50 43 21 g SQR V=Sqrt(V*V+2gX)
51 16 CHS Show crash as down
52 44 1 STO 1 V
53 45 1 RCL 1 Jump here if hit ground
54 42 0 f 0
55 43,33 0 g GTO 00 --> Stop

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