The Museum of HP Calculators
The Museum of HP Calculators
This program was first published in the HP-41C Users' Library Solutions: Games by Hewlett-Packard and is used here by permission.
This program is supplied without representation or warranty of any kind. Hewlett-Packard Company 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.
N atoms are randomly placed in a black box with dimensions l0x10. No atom can be on the edge of the box. By firing particles into the box from the edges, and noting their exit locations, you attempt to find the atom positions. For a single atom, the scatters and reflections are as shown in Figure 1. Multiple atom scatters are simple extensions of this diagram: See, for examples, Figures 2 and 3. Note in particular, the back reflections of Figure 3 which arise from two combined scatters. More complex scattering and reflection are shown in Figure 4 where atom 4 causes scatter A, atom 2 causes B, 1 causes C, 4 (again) causes D, 3 causes E, and atom 1 reflects the particle back along the convoluted path. The numbering of the box grid is given in Figure 5. The 5th position on the base has coordinates 5.0, the 7th on the right is 9.7, and so on.
You select the value of N, and the machine places the N atoms randomly. You then fire particles from the edge: The machine tracks them and displays the output edge locations. At any time you can get the machine to confirm or reject any suspected atom location. If the guess is wrong, you are "penalized" by having the number of used particles increased by 5. The object of the game is not only to find the atoms, but to do so with the minimum number of probes.
NOTE: Although 9 atoms may be placed, a "good" game is 4 or 5.
Diagrams
Note: Requires 1 Memory Module on HP-41C
|
Step |
Instructions |
Input Data/Units |
Keys |
Output Data/Units |
|
1 |
Enter program |
|||
|
2 |
Initialize |
|
[XEQ] SCATTER |
SEED? |
|
3 |
Key in number between 0 and 1 |
seed |
[R/S] |
NO. OF ATOMS? |
|
4 |
Key in number of atoms to be placed. |
N |
[R/S] |
READY |
|
5 |
Key in an entrance point. |
x.y |
[R/S] |
(x).(y) |
|
6 |
To guess a position key one in. |
x.y |
[A] |
YES (or) NO |
|
( ) PROBES |
||||
| Continue with steps 5 and 6 as desired. | ||||
|
7 |
To start a new game go to step 4. |
|
[E] |
NO. OF ATOMS? |
|
8 |
If at any time you give up you can find all positions. |
[C] |
(x).(y) . . . |
Set up and find 4 atoms
Keystrokes: Display:
[XEQ] [ALPHA]
SIZE [ALPHA] 022
[XEQ] [ALPHA]
SCATTER [ALPHA] SEED?
.191062 [R/S] NO. OF ATOMS?
4 [R/S] READY
2.0 [R/S] 0,2
4.0 [R/S] 9,2
3.3 [A] YES
2 PROBES
6.9 [R/S] 6,9
6.8 [A] NO
8 PROBES
0.8 [R/S] 9,8
. .
. .
LINE KEYS 01LBL "SCATTER" Initialize 02 SF 27 03 CF 29 04 SF 28 05 FIX 0 06 "SEED?" 07 PROMPT 08 STO 00 09
," 150 ARCL 14 151 AVIEW 152 GTO 20 153
R00 Seed R01 Atom Location R02 Atom Location R03 Atom Location R04 Atom Location R05 Atom Location R06 Atom Location R07 Atom Location R08 Atom Location R09 Atom Location R10 n R11 Probe count R12 particle x R13 particle y R14 x R15 y R16 Used R17 Used R18 Used R19 Used R20 Used R21 Used
00 Top or bottom / Left or right 01 Top or right / Bottom or left 02 Used 03 Used
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