Memory Game for the HP-25/25C/33E/33C

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This game first appeared in the V6N5P10 PPC Journal in August 1979 by Bill Derrick. Thanks to Bill wherever he is today!

User Instructions: 1) Key in program, 2) Press f PRGM (out of program mode of course or else you'll erase what you just keyed in), 3) Enter a non-zero seed and press R/S, 4) See memory number displayed for just an instant, 5) Calculator will stop and display a zero, 6) Enter your guess as to what the number was and press R/S again, 7) Steps 5 and 6 will be repeated 10 times, 8) After 10 times, your score is displayed, 9) To repeat the game, go back to step 3.

Number correct indicates how good your memory is. 1-5 Correct = senile to poor memory, 6 = average, 7 = good, 8 = superior, 9 or 10 = why are you wasting your time doing this?

Program Listing To change this program so that it will run on the HP-33 calculator, make the following changes: Steps 16-20 should be: RCL 1, RCL 2, f X > Y, GTO 39, and g NOP. Steps 39 - 43 should be: X <> Y, RCL 3, -, R/S, GTO 07. That's it!

Line      Instruction
01         f FIX 0
02         f REG
03         STO 0
04         1
05         0
06         STO 1
07         1
08         STO 2
09         0
10         STO 3
11         RCL 0
12         g PI
13         *
14         g FRAC
15         STO 0
16         RCL 2
17         RCL 1
18         f X < Y
19         GTO 39
20         X <> Y
21         RCL 3
22         -
23         f Y^X
24         *
25         f INT
26         g X = 0?
27         GTO 11
28         f PAUSE
29         0
30         R/S
31         +
32         /
33         1
34         STO+ 2
35         f X = Y?
36         0
37         STO+ 3
38         GTO 11
39         RCL 3
40         -
41         R/S
42         GTO 07

That's all there is to it. Enjoy!