The Museum of HP Calculators


NIM for the HP-12C

This program is by Paul Dale and is used here by permission.

This program is supplied without representation or warranty of any kind. Paul Dale 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 the basic game of NIM.

To run it, f CLEAR PRGM (not in program mode), enter the number in the pile and press R/S. You and the calculator will take turns taking from 1 to 3 from the pile, whoever takes the last one loses. You know it is your turn when the pile's remaining count is displayed negative.

After you turn, the new pile count will display followed by the calculator's grab count.

Turn the calculator upside down at the end of the game.

Listing

01  STO 0
02  4           One more than the maximum that can be taken
03  STO 1
04  FIX 0
05* RCL 0       Start of main game loop
06  CHS
07  R/S         Player's input
08  INTG
09  0
10  x<>y
11  x<=y?       Player tried something too small
12  GTO 05
13  RCL 1
14  x<=y?       Player tried something too large
15  GTO 05
16  x<>y
17  STO- 0
18  e^x
19  STO+ 02     Push some fuzzyness into our random number
20  0
21  RCL 0
22  x<=y?       Has the player lost?
23  GTO 35
24  2
25  x<=y?       Is there more than one left?
26  GTO 41
27  FIX 1       We lost!
28  3
29  5
30  0
31  7
32  .
33  1
34  GTO 00
35* 5           We won!
36  5
37  1
38  7
39  8
40  GTO 00
41* RCL 0       Display the adjusted total
42  PSE         
43  1           Figure out our move
44  -
45  RCL 1
46  /
47  FRAC
48  RCL 1
49  *
50  x=0?        Is the ideal count unachievable?
51  GTO 55
52* STO- 0      Adjust & display our grab
53  PSE
54  GTO 05
55* RCL 2       Generate a random selection
56  EEX
57  3
58  *
59  FRAC
60  RCL 2
61  EEX
62  5
63  /
64  +
65  FRAC
66  STO 2
67  RCL 1       Scale to proper range
68  1
69  -
70  *
71  1
72  +
73  INTG
74  GTO 52

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