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Cyber Tennis Game for HP-41C
09-02-2017, 08:01 PM (This post was last modified: 09-05-2017 11:40 PM by Namir.)
Post: #1
Cyber Tennis Game for HP-41C
The game assumes you are playing a 10-point match of cyber tennis. You play as many rounds until either you or the calculator wins 10 rounds. See instructions to play the game.

Memory Map

Code:
R00 = random number
R01 = counter for player
R02 = counter for calculat0r
R03 = win count
R04 = max range

HP-41C Listing

Code:
LBL "TENNIS"
LBL a
0
STO 01
STO 02
10
STO 03
X^2
STO 04

LBL A        # main game routine
RCL 01        
RCL 03
X=Y?        # did the player win the game?
GTO B
RCL 02
X=Y?        # did the calculator win the game?
GTO C
RCL 00
"SEED?"
FC? 00        # check flag 00 for no-prompt mode
PROMPT        # prompt for next seed (optional)
STO 00
XEQ 01        # get random integer for player
XEQ 01        # get random integer for calculator
X>Y?        # did the calculator win current round?
GTO 02
X<>Y
X>Y?        # did the player win the current round?
GTO 03
"TIE"
AVIEW        
PSE        # no one won the current round
GTO A

LBL 02        # increment calculator wins
1
STO+ 02
"CALC:"
ARCL 02
AVIEW
PSE        # display calculator's winning
GTO A

LBL 03        # increment player's wins
1
STO+ 01
"YOU:"
ARCL 01
AVIEW
PSE        # display as player's number
GTO A

LBL B        # Player wins the game
"YOU WIN"
GTO 04

LBL C        # Calculator wins the game
"YOU LOSE"

LBL 04
BEEP
PROMPT
RTN

LBL 01        # get random integer
XEQ E
RCL 04
*
INT
RTN

LBL E        # PRNG function
RCL 00
PI
+
5
Y^X
FRC
STO 00
RTN

Games Instructions

1) Press [XEQ]"TENNIS or [shift][A] (in User Mode) to initialize the game.
2) The program stops to display current seed. You can alter this value or enter a new one. The new "seed" can be an integer, a fraction, or a number contains both.
3) Press [R/s]. The program determines who wins the current round:
A) If the player wins, the program pauses and displays "YOU:" followed by current total wins for the player.
B) If the calculator wins, the program pauses and displays "CALC:" followed by the current total wins for the calculator.
C) If no one wins the current round, the program pauses and displays "TIE".

4) Repeat steps 2 and 3. If the player wins, the program displays "YOU WIN". If the calculator wins, the program displays "YOU LOSE".

Note: You can set flag 00 to skip the "SEED?" prompt.
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09-03-2017, 05:25 PM (This post was last modified: 09-03-2017 08:46 PM by Dieter.)
Post: #2
RE: Cyber Tennis Game for HP-41C
(09-02-2017 08:01 PM)Namir Wrote:  Note: You can set flag 00 to skip the "SEED?" prompt.

If this is the intended behaviour the FC? 00 test has to move down one step between "SEED?" and PROMPT.
The comment at LBL 02 says that a negative number is displayed. That's not correct, all output is positive.
LBL 01 generates a random integer between 0 and 99. This score is never displayed, so the routine can be completely removed and all calls replaced by XEQ E. This way also all references to R04 are obsolete. Since the probability of a tie then is near zero that part of the code can be removed as well. ;-)
The program does not set the display mode. At least a FIX 0 and preferably also a CF 29 in the initialization routine is recommended.

Dieter
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09-05-2017, 02:59 PM
Post: #3
RE: Cyber Tennis Game for HP-41C
(09-03-2017 05:25 PM)Dieter Wrote:  
(09-02-2017 08:01 PM)Namir Wrote:  Note: You can set flag 00 to skip the "SEED?" prompt.

If this is the intended behaviour the FC? 00 test has to move down one step between "SEED?" and PROMPT.
The comment at LBL 02 says that a negative number is displayed. That's not correct, all output is positive.
LBL 01 generates a random integer between 0 and 99. This score is never displayed, so the routine can be completely removed and all calls replaced by XEQ E. This way also all references to R04 are obsolete. Since the probability of a tie then is near zero that part of the code can be removed as well. ;-)
The program does not set the display mode. At least a FIX 0 and preferably also a CF 29 in the initialization routine is recommended.

Dieter

Edited listing's erroneous comments.
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09-05-2017, 04:59 PM
Post: #4
RE: Cyber Tennis Game for HP-41C
(09-05-2017 02:59 PM)Namir Wrote:  Edited listing's erroneous comments.

Hello Namir,

What Dieter was trying to convey in his first remark, was this piece of code
Code:
RCL 00
FC? 00        # check flag 00 for no-prompt mode
"SEED?"
PROMPT        # prompt for next seed (optional)
STO 00

should be modified to
Code:
RCL 00
"SEED?"
FC? 00        # check flag 00 for no-prompt mode
PROMPT        # prompt for next seed (optional)
STO 00

Best regards,

Sylvain
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09-05-2017, 08:32 PM (This post was last modified: 09-06-2017 12:04 PM by Dieter.)
Post: #5
RE: Cyber Tennis Game for HP-41C
(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
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09-05-2017, 11:41 PM
Post: #6
RE: Cyber Tennis Game for HP-41C
(09-05-2017 04:59 PM)Sylvain Cote Wrote:  
(09-05-2017 02:59 PM)Namir Wrote:  Edited listing's erroneous comments.

Hello Namir,

What Dieter was trying to convey in his first remark, was this piece of code
Code:
RCL 00
FC? 00        # check flag 00 for no-prompt mode
"SEED?"
PROMPT        # prompt for next seed (optional)
STO 00

should be modified to
Code:
RCL 00
"SEED?"
FC? 00        # check flag 00 for no-prompt mode
PROMPT        # prompt for next seed (optional)
STO 00

Best regards,

Sylvain

Fixed the location of FC?00 command.
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09-06-2017, 11:26 AM (This post was last modified: 09-06-2017 12:09 PM by Dieter.)
Post: #7
RE: Cyber Tennis Game for HP-41C
(09-05-2017 11:41 PM)Namir Wrote:  Fixed the location of FC?00 command.

Fine. But there still is one thing I do not understand: With flag 0 cleared program prompts for a seed in every single round of the match. Is there a special reason for this, or why don't you just put the seed prompt into the initialisation routine at LBL a so that it only appears when a new match is started – like in most other games programs? This also would make the whole flag 0 thing obsolete.

Just curious,

Dieter
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