Cyber Tennis Game for HP-41C

[Dieter]

(09-05-2017 02:59 PM)Namir Wrote:  Edited listing's erroneous comments.

OK, but this does not change the way the program works, cf. Sylvain's explanation.

Anyway... as you may know from earlier posts I'm a big fan of short and effective code, especially in programs for calculators with their limited ressources. Below is my attempt at a very streamlined version of "tennis". Maybe you can try it and see how you like it. It requires just R0...R2 and 43 steps.

Code:

01  LBL"TENNIS"
02  RCL 00
03  "SEED?"         ; prompt for random seed
04  PROMPT          ; just press R/S to continue with the current seed
05  STO 00
06  LBL 01          ; new match starts here
07  CLX
08  STO 01          ; reset your score
09  STO 02          ; reset calculator's score
10  LBL 02          ; new round starts here
11  RCL 00
12  Pi
13  +               ; generate a pseudo random number
14  X^2
15  FRC
16  STO 00          ; X = 0...0,999999999
17  ST+ X           ; X = 0...1,999999998
18  SIGN            ; X = 1, L = 0...1,999999998
19  ST+ L           ; X = 1, L = 1...2,999999998
20  ST+ IND L       ; add 1 to R01 (your score) or R02 (calculator's score)
21  FIX 0
22  CF 29
23  "YOU: "         ; build score message
24  ARCL 01
25  "├ 41C: "
26  ARCL 02
27  FIX 4           ; on a 41CX or with an X-Func module you may use "RCLFLAG" before FIX 0 
28  SF 29           ; and "STOFLAG" after ARCL 02 instead of these two lines
29  AVIEW           ; display scores
30  PSE
31  10
32  RCL IND L       ; has last updated score reached 10 points?
33  X<Y?            ; if still less
34  GTO 02          ; do another round
35  "YOU LOSE"      ; match finished, set "you lose" message first
36  RCL 02
37  RCL 01
38  X>Y?            ; if your score is higher than calculator's
39  "YOU WIN"       ; set "you win"  message
40  AVIEW
41  BEEP
42  RTN
43  GTO 01          ; press [R/S] for another match

The flag 0 skip of the seed prompt has been omitted as I think that simply pressing [R/S] instead is even easier than setting a flag manually. Also a seed input is not required in every single round but only once when the program starts.

Edit: updated listing to add comments and annotations

Dieter