Swiss Micros DM42 and HP 42S: Moon Landing Simulator from the HP 33-E Applications Book
Landing the Rocket
The goal is to provide enough fuel to get the rocket to land on the moon safely. The use of fuel pushes the rocket away from the surface and slow down the descent. Don’t crash or use too much fuel to escape into space.
Variables:
X: Position
V: Velocity
F: Fuel
G: Gravity
B: Amount of Fuel to burn
Initial Values (from the HP-33E Applications):
X = 500
V = -50
F = 120
G = 5
I wasn't sure about the win condition (X = 0, V = 0?).
I show the position, velocity, and fuel after each successful turn. Enter the amount of units to burn at the burn prompt.
Download here: https://drive.google.com/file/d/1YsYzIMxALuRx_MHSSzGFFEQJdrN656DS/view?usp=sharing
DM42 and HP 42S Code: MOON
00 { 184-Byte Prgm }
01▸LBL "MOON"
02 500
03 STO "X"
04 -50
05 STO "V"
06 120
07 STO "F"
08 5
09 STO "G"
10▸LBL 01
11 "POS:"
12 ARCL "X"
13 AVIEW
14 STOP
15 "VEL:"
16 ARCL "V"
17 AVIEW
18 STOP
19 "FUEL:"
20 ARCL "F"
21 AVIEW
22 STOP
23 RCL "X"
24 X=0?
25 GTO 07
26▸LBL 02
27 "BURN?"
28 PROMPT
29 STO "B"
30 RCL "F"
31 X<Y?
32 GTO 05
33▸LBL 03
34 RCL "B"
35 STO- "F"
36 RCL- "G"
37 STO "A"
38 RCL "V"
39 RCL+ "X"
40 RCL "A"
41 2
42 ÷
43 +
44 STO "X"
45 X≥0?
46 GTO 04
47 GTO 06
48▸LBL 04
49 RCL "V"
50 RCL+ "A"
51 STO "V"
52 GTO 01
53▸LBL 05
54 2
55 RCL× "G"
56 RCL "V"
57 X↑2
58 +
59 SQRT
60 +/-
61 STO "V"
62▸LBL 06
63 "VEL:"
64 ARCL "V"
65 AVIEW
66 "YOU LOSE"
67 AVIEW
68 RTN
69▸LBL 07
70 "SUCCESS!"
71 AVIEW
72 .END.
Example Game
XEQ "MOON"
Initial Turn
POS: 500
VEL: -50
FUEL: 120
BURN? 0
POS: 447.5
VEL: -55
FUEL: 120
BURN? 0
POS: 390
VEL: -60
FUEL: 120
BURN? 0
POS: 327.5
VEL: -65
FUEL: 120
BURN? 5
POS: 262.5
VEL: -65
FUEL: 115
BURN? 0
POS: 195
VEL: -70
FUEL: 115
BURN? 5
POS: 125
VEL: -70
FUEL: 115
BURN? 10
POS: 57.5
VEL: -65
FUEL: 100
BURN? 12.5
"YOU LOSE" -3.75
So close. Good luck!
Source
HP-33 Applications. Hewlett Packard. Corvallis, OR. February 1978
Eddie
All original content copyright, © 2011-2024. Edward Shore. Unauthorized use and/or unauthorized distribution for commercial purposes without express and written permission from the author is strictly prohibited. This blog entry may be distributed for noncommercial purposes, provided that full credit is given to the author.
