TI-57 Lunar Lander ?

[Thomas Klemm]

(06-04-2022 06:22 PM)pauln Wrote:  

Code:

# Loops 4 times (4 seconds)
5 STO 0 Lbl 0 INV Dsz RST

I was not sure whether to trust the comment or the code.
Therefore I changed it to:

Code:

# Loops 4 times (4 seconds)
4 STO 0 Lbl 0 INV Dsz RST

With this I came up with the following solution to a safe landing:

100.
100.2500

5 R/S

95.
100.2200

5 R/S

90.
100.1900

5 R/S

85.
100.1600

5 R/S

80.
100.1300

5 R/S

75.
100.1000

10 R/S

65.
85.0715

10 R/S

55.
70.0475

10 R/S

45.
55.0280

10 R/S

35.
40.0130

10 R/S

25.
25.0025

25 R/S

»5.0000«

That was surprisingly fun to figure out.

---

Here's a mostly verbatim translation of the program for the HP-42S:

Code:

00 { 92-Byte Prgm }
01▸LBL "LUNAR"
02 2500
03 STO 02
04 100
05 STO 01
06 STO 03
07▸LBL 01
08 "Fuel: "
09 ARCL 03
10 ├" Vel: "
11 ARCL 01
12 ├"[LF]Alt: "
13 ARCL 02
14 PROMPT
15 RCL 03
16 X>Y?
17 X<>Y
18 STO 04
19 STO- 03
20 4
21 STO 00
22▸LBL 00
23 DSE 00
24 FS? 00 # assume it is clear
25 GTO 01
26 RCL 01
27 STO- 02
28 5
29 STO+ 01
30 RCL 04
31 STO- 01
32 RCL 02
33 X<0?
34 GTO 07
35 6
36 RCL 01
37 ABS
38 RCL 02
39 +
40 X≥Y?
41 GTO 00
42 END