The fun thing about that is the entire map is generated by something like 50 bytes of code. (Yes, bytes.) As far as I know, it goes through all 256 screens. I could swear there used to be a whole world map online, but I’m having difficulty locating it.
Actually, here’s a map, and if I’m reading it right, that one shows 255 unique screens.
Other sources online do seem to indicate it’s 255, not 256 screens, so it looks like you have everything.
I would be extremely surprised if it were 255, since it would take slightly more space to program for 255 screens than 256, and with space at as much of a premium as it was, there’s no way they’d do that (especially not to shrink the world).
The “rooms” are algorithmically generated. See my note about how the whole map fits in under 50 bytes.
Yes, and the algorithm is simpler for 256 rooms than for 255. With 256, every time you change screens, you can just add or subtract 1 from the seed. With 255, you’d have to add or subtract one, and then check to see if you’re on the skipped seed, and go another step if you are. There’s no way they’d put in a complication like that.
I just programmed the algorithm using the source code (and then looking up to see if someone already did the work doing it in C or C++) for Pitfall and, indeed, it loops back to the initiall value after 255. The output of “0” is not represented, so that’s the number missing.
The source I found was disassembled and commented on by Thomas Jentzsch. You can find it here.
In the top of the file, it says:
Note: 255 screens.
The seed for the scene/“random” number generator is 0xc4, or 196. Here is the result of running the generator through all its values:
OUTPUT ITERATION
196 0 (SEED)
137 1
18 2
37 3
75 4
151 5
46 6
92 7
184 8
112 9
224 10
192 11
129 12
3 13
6 14
12 15
25 16
50 17
100 18
201 19
146 20
36 21
73 22
147 23
38 24
77 25
155 26
55 27
110 28
220 29
185 30
114 31
228 32
200 33
144 34
32 35
65 36
130 37
5 38
10 39
21 40
43 41
86 42
173 43
91 44
182 45
109 46
218 47
181 48
107 49
214 50
172 51
89 52
178 53
101 54
203 55
150 56
44 57
88 58
176 59
97 60
195 61
135 62
15 63
31 64
62 65
125 66
251 67
246 68
237 69
219 70
183 71
111 72
222 73
189 74
122 75
245 76
235 77
215 78
174 79
93 80
186 81
116 82
232 83
209 84
162 85
68 86
136 87
16 88
33 89
67 90
134 91
13 92
27 93
54 94
108 95
216 96
177 97
99 98
199 99
143 100
30 101
60 102
121 103
243 104
231 105
206 106
156 107
57 108
115 109
230 110
204 111
152 112
49 113
98 114
197 115
139 116
22 117
45 118
90 119
180 120
105 121
210 122
164 123
72 124
145 125
34 126
69 127
138 128
20 129
41 130
82 131
165 132
74 133
149 134
42 135
84 136
169 137
83 138
167 139
78 140
157 141
59 142
119 143
238 144
221 145
187 146
118 147
236 148
217 149
179 150
103 151
207 152
158 153
61 154
123 155
247 156
239 157
223 158
191 159
126 160
253 161
250 162
244 163
233 164
211 165
166 166
76 167
153 168
51 169
102 170
205 171
154 172
53 173
106 174
212 175
168 176
81 177
163 178
70 179
140 180
24 181
48 182
96 183
193 184
131 185
7 186
14 187
29 188
58 189
117 190
234 191
213 192
170 193
85 194
171 195
87 196
175 197
95 198
190 199
124 200
249 201
242 202
229 203
202 204
148 205
40 206
80 207
161 208
66 209
132 210
9 211
19 212
39 213
79 214
159 215
63 216
127 217
255 218
254 219
252 220
248 221
240 222
225 223
194 224
133 225
11 226
23 227
47 228
94 229
188 230
120 231
241 232
227 233
198 234
141 235
26 236
52 237
104 238
208 239
160 240
64 241
128 242
1 243
2 244
4 245
8 246
17 247
35 248
71 249
142 250
28 251
56 252
113 253
226 254
196 255
137 256
Note that the seed, 196, appears at count 0 and count 255, so the pattern repeats after 255, not 256 iterations. Note that “0” as an output does not appear. Entering “0” as the seed value results in constant output of 0.
And here is the C code implementation of the assembly source that I used, if you want to check. That’s 15 bytes long in assembly, but note that’s only half of the map generation code (this is what happens when you go rightward in the world), and doesn’t include some branching.
Wait…you’re married???
She must really love you to let you paint the garage doors that way.
…Or she loves Pitfall.
It took me a couple years just to get my wife to let me paint the front door red.
My hat’s off to you!
Well she was kind of hesitant at first but it obviously meant a lot to me and I really wanted to do it, so she’s rolling with it and some of my other ideas. She only likes angry birds and bejewelled type phone games, but she is in all other ways my sweetie, so we’ll celebrate 5 years at the end of this summer 
Oh, and I talked her into doing a mostly red porch 
Ok, I’d like to get the Atari and the game within the next few weeks and start the painting at some point in april.
I got an art tablet that has sheets of tracing paper between thin plastic sheets you can cut stencils out of. I have 10x17 printouts I was going to use to draw/trace the objects out, then stencil. But…
I’m thinking about doing this one. The question I have is: my printouts are 10X17cm, how do I change the image to print at 12x20cm? I just have whatever program windoze 10 uses by default to print and it has some size options but not 12x20cm.
pulykamell: er, yes that Thomas Jentzsch’s descriptions are a bit confusing because he keeps using the word “random”. I do not think that word means what he thinks it means. 
But I’ve done a few languages of programming back in the day, and I’d love to have all the original code (and many other games from back then) and analyze it. Maybe I could then make my own Pitfall sequels! 
Yeah, it’s a pseudo-random generator called a linear feedback shift register (LFSR). While he does say “randomly,” he immediately says that it’s through a bi-directional LFSR, so if you know what an LFSR is, you’d know it’s more accurately referred to as a pseudo-random number generator. Perhaps he should have used that term or caged the word “random” in quotes.
As far as the code goes, that is all the Pitfall code. You can modify it, reassemble it, and run it on an Atari 2600 emulator (Stella is the one I used.) I’ve done it, but all I did was change the starting seed value for the in LFSR, so I’d get a different map (or, really, a different starting point for the map; the “random” number sequence is still the same, just starting from a different point.)
ETA: Oh, and, sorry, you’ll need a 6502 assembler to generate the machine code before you run it through the emulator. I used DASM.
Yes, but putting it in quotes would have cost him 16 bits of storage for the quote characters, and adding the pseudo- prefix would have cost him a whopping 56 bits. There’s no way he could afford that much bloat!
^
I should add, if you are really interested, check out the Atari Age website. That has a whole mess of Atari 2600 programming resources. I don’t know if there’s any higher language level tools available out there, but most of the Atari 2600 programming I’ve seen requires knowledge of the 6502 instruction set/assembly language programming (same processor as used in the early Apples, Commodores, NES, etc.) There apparently is a BASIC compiler available, but programming the 2600 really requires knowledge of assembly. If you dig, you can find the disassemblies and commented source code versions of a number of 2600 cartridges.
Two points:
(1) You are talking about a HELLUVA lot of teensy tiny detail painting, vertical, no less. . . And you’re on disability? I hurt all over just contemplating the task! The stretching, climbing up on ladders or boxes, bending double or laying on your stomach for the bottom row. Ow!
(2) Stencil work is messy. Potentially bloody, too, if you make your own stencils. Make sure you practice A LOT before you start on the actual garage doors! I’d recommend a sponge for painting, instead of gobs of paint on a brush. The paint loves to run under the stencil.
Personally, I’d take the screenshots to a graphics shop and tell them what you want to do. Perhaps they can make a transfer or a decal. And then go to a decent paint store and get advice on the best painted surface for this decal. Don’t worry, you’ll still get a chance to measure and calculate and create and contort your body! I just think you’ll get a better finished project that would also better accommodate your disabled status.
~VOW
I personally like the free program IrfanView. The print menu has all kinds of options for custom sizes, and allows selecting the proper unit (cm vs. inches). Uncheck “aspect ratio” so that it doesn’t try to calculate it for you–although in principle the size should be 20x11.764, in practice you won’t notice the difference between that and 20x12, and it’ll just make the calculations annoying.