TI-57 Lunar Lander ?
06-04-2022, 06:22 PM (This post was last modified: 06-04-2022 08:19 PM by pauln.)
Post: #21
 pauln Member Posts: 84 Joined: May 2022
RE: TI-57 Lunar Lander ?
I have been looking for a Lunar Lander for TI-57/RCL-57 and I came across this older thread. I ended up writing my own version which I list here for anyone interested.

IMO, it has a few advantages over the one in "L'Ordinateur de Poche":
• It displays the sign of the velocity, making clear whether the rocket is descending or not
• There is no need to enter the fix mode
• It gives a clear indication that the game has ended (display blinking)
• It computes velocity and altitude every second, looking for landing or a crash, instead of doing so only every 10 seconds

Instructions:
1. Key in the program
2. Enter initial velocity: 100 STO 1
3. Enter initial altitude: 2500 STO 2
4. Enter initial fuel: 100 STO 3
5. RST R/S
You should see "100" (fuel) followed by "100.2500" (velocity.altitude).
6. 'N' R/S
where 'N' (N integer >= 0) is the number of gallons to consume in the next 4 seconds.
You should see "fuel" and, after a pause, "velocity.altitude"
7. Repeat Step 6 until the display blinks
if >= 0, you landed safely
if < 0, you crashed

If you want to see your final velocity, press RCL 1.

Code:
 # Displays the current state. RCL 3 INV Fix Pause                    # Fuel  RCL 1 x:t 1 +/- INV x>=t +/-           # Compute sign of velocity x RCL 2 / 4 INV log + RCL 1 = Fix 4      # velocity.altitude R/S # Updates the fuel available STO 4                                  # Number of gallons for the next 4 seconds x:t RCL 3 INV x>=t STO 4               # Ensure it doesn't exceed quantity of fuel left RCL 4 INV SUM 3                        # Update fuel # Loops 4 times (4 seconds) 5 STO 0 Lbl 0 INV Dsz RST # Updates the altitude and velocity after 1 second RCL 1 INV SUM 2                        # Altitude 5 SUM 1 RCL 4 INV SUM 1                # Velocity # Determines what happened in the last second RCL 2 C.t INV x>=t GTO 7               # Crash: note the non existent label 7 6 x:t RCL 1 |x| + RCL 2 = x>=t GTO 0         # Not landing: loop back # Safe landing: if |velocity| + altitude <= 5, the display will blink (>= 0) since GTO 0 is at the last step (49)
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 Messages In This Thread TI-57 Lunar Lander ? - Gene - 02-02-2019, 06:11 PM RE: TI-57 Lunar Lander ? - Didier Lachieze - 02-02-2019, 06:31 PM RE: TI-57 Lunar Lander ? - badaze - 02-02-2019, 07:37 PM RE: TI-57 Lunar Lander ? - Thomas Klemm - 02-02-2019, 07:32 PM RE: TI-57 Lunar Lander ? - Thomas Klemm - 02-02-2019, 08:46 PM RE: TI-57 Lunar Lander ? - Valentin Albillo - 02-02-2019, 09:31 PM RE: TI-57 Lunar Lander ? - Thomas Klemm - 02-02-2019, 10:32 PM RE: TI-57 Lunar Lander ? - ijabbott - 02-03-2019, 08:09 AM RE: TI-57 Lunar Lander ? - EdS2 - 02-03-2019, 09:26 AM RE: TI-57 Lunar Lander ? - David Hayden - 02-07-2019, 07:54 PM RE: TI-57 Lunar Lander ? - Thomas Klemm - 02-03-2019, 11:34 AM RE: TI-57 Lunar Lander ? - Thomas Klemm - 02-03-2019, 11:35 AM RE: TI-57 Lunar Lander ? - EdS2 - 02-04-2019, 12:17 PM RE: TI-57 Lunar Lander ? - Thomas Klemm - 02-04-2019, 08:50 PM RE: TI-57 Lunar Lander ? - StephenG1CMZ - 02-06-2019, 10:42 PM RE: TI-57 Lunar Lander ? - Thomas Okken - 02-04-2019, 10:42 PM RE: TI-57 Lunar Lander ? - Paul Dale - 02-07-2019, 04:27 AM RE: TI-57 Lunar Lander ? - Thomas Okken - 02-07-2019, 05:35 PM RE: TI-57 Lunar Lander ? - SlideRule - 02-05-2019, 01:45 PM RE: TI-57 Lunar Lander ? - Gamo - 02-06-2019, 05:10 AM RE: TI-57 Lunar Lander ? - pauln - 06-04-2022 06:22 PM RE: TI-57 Lunar Lander ? - Thomas Klemm - 06-12-2022, 07:00 PM RE: TI-57 Lunar Lander ? - Thomas Klemm - 06-12-2022, 07:13 PM RE: TI-57 Lunar Lander ? - pauln - 06-12-2022, 07:38 PM

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