The Museum of HP Calculators The Museum of HP Calculators
This program was first published in the HP-41C Users' Library Solutions: Games by Hewlett-Packard and is used here by permission.
This program is supplied without representation or warranty of any kind. Hewlett-Packard Company and The Museum of HP Calculators therefore assume no responsibility and shall have no liability, consequential or otherwise, of any kind arising from the use of this program material or any part thereof.
This program pits the HP-41C against a human opponent in a game of 3-D Tic Tac Toe. The rules of this game are simple:
1) The board consists of 4 levels, each of which is 4 rows deep and 4 columns across, making a total of 64 squares on a 3 dimensional board.
2) Two players move alternately by placing a black or white marker on a square (or making an X or a O on a paper layout of the board). Once a move is made, the piece is never moved or removed. In this game, the human always goes first.
3) A player wins by placing four markers in a straight line. The line can lie in more than one level, and diagonals are perfectly legitimate wins.
In short, the game is played just like regular Tic Tac Toe, except that the board has one additional dimension, and is one square bigger in all dimensions. Unlike regular Tic Tac Toe, there is no known winning strategy for the 3-D version. It is a much more complex game which can require considerable skill in a player, allowing for very complicated strategies.
The 41C plays and remembers the game by dividing the board into its 16 component rows and storing an entire row in one register. The registers R0 through R15 are reserved for the game board.
Each square on the board can be characterized by its level=z, its row=y and its column=x. x,y, and z can have values from 1 through 4. When entering moves, make sure they are 3 digit numbers. All three digits must be between 1 and 4 inclusive. Entering a move outside this range may cause the program to make erroneous entries in the board.
The boards look like:
Note:Requires 2 Memory Modules for use on the HP-41C.
| Step | Instructions | Input Data/Units | Keys | Output Data/Units |
| 1 | Enter program | |||
| 2 | Initialize | [XEQ] 3DTTT | READY | |
| 3 | Key in your move | xyz | [R/S] | MY MOVE: |
| Repeat 3 until you win or lose |
Keystrokes: Display: [XEQ] [ALPHA] SIZE [ALPHA] 026 [XEQ] [ALPHA] 3DTTT [ALPHA] READY 242 [R/S] MY MOVE: 322 414 [R/S] MY MOVE: 134 123 [R/S] MY MOVE: 234 441 [R/S] MY MOVE: 423 141 [R/S] MY MOVE: 232 214 [R/S] MY MOVE: 114 424 [R/S] MY MOVE: 434 111 [R/S] 334, I WIN
The boards look like:
LINE KEYS 001 ◆LBL "3DTTT" ; Initialize 002 FIX 0 003 CLRG 004 CF 00 005 CF 01 006 CF 02 007 CF 03 008 CF 29 009 "READY" 010 AVIEW ;_________________ 011 ◆LBL A 012 STOP 013 1 E3 ; Input players 014 / ; move 015 STO 19 016 0 017 STO 16 018 2 019 STO 17 020 RDN 021 RDN 022 XEQ 10 023 STO 25 024 RCL 20 025 RCL IND 25 026 * 027 INT 028 1 E2 029 / 030 FRC 031 "ILLEGAL MOVE" 032 X≠0? 033 AVIEW ; Illegal move 034 X≠0? 035 GTO A 036 5 037 RCL 20 038 / 039 1 040 + ; Store move 041 S1+ IND 25 042 RCL 18 043 X=0? 044 GTO 01 045 SF 00 ; Test move 046 XEQ 04 047 CF 02 048 CF 03 049 CF 00 050 .06 051 RCL 18 052 FRC 053 STO 18 054 X>Y? 055 GTO 02 056 X=Y? 057 GTO 03 058 ◆LBL 01 ;_________________ 059 1 E-2 060 ST+ 18 ; Increment round count 061 SF 02 062 GTO 03 063 ◆LBL 02 ;_________________ 064 XEQ 10 065 XEQ 04 ; Test machine move 066 FS?C 02 067 GTO 03 068 RCL 19 069 XEQ 10 070 ◆LBL 03 071 RCL 16 072 INT 073 1 074 - 075 3 076 / 077 21 078 + 079 ENTER↑ 080 FRC 081 X=0? 082 CF 01 083 .5 084 X>Y? ; Jump to proper 085 SF 00 ; test routine 086 GTO IND Z 087 ◆LBL 10 ;_________________ 088 10 ; Parse move 089 * 090 INT 091 LASTX 092 FRC 093 10 094 * 095 INT 096 LASTX 097 FRC 098 .5 099 - 100 CHS 101 20 102 * 103 10↑X 104 STO 20 105 RDN 106 1 107 - 108 STO 21 109 X<>Y 110 1 111 - 112 4 113 * 114 STO 22 115 + 116 STO 23 117 RTN ;_________________ 118 ◆LBL 04 119 1 ; Initialize test controls 120 RCL 22 121 XEQ 01 122 4 123 RCL 21 124 XEQ 01 125 5 126 ENTER↑ 12Z 0 128 XEQ 01 129 3 130 ENTER↑ 131 XEQ 01 132 0 133 STO 24 134 RCL 23 135 STO 25 136 GTO 02 137 ◆LBL 01 ;_________________ 138 CF 01 139 STO 25 ; Set test points 140 RDN 141 STO 24 142 XEQ 02 143 SF 01 144 RCL 24 145 CHS 146 STO 24 147 XEQ 02 148 RCL 24 149 CHS 150 STO 24 ;_________________ 151 ◆LBL 02 152 1 ; Testing cycle 153 ST+ 18 154 1 E2 155 ENTER↑ 156 ENTER↑ 157 RCL IND 25 158 X<> 25 159 RCL 24 160 + 161 X<> 25 162 FS? 01 163 * 164 RCL IND 25 165 + 166 X<> 25 167 RCL 24 168 + 169 X<> 25 170 FS? 01 171 * 172 RCL IND 25 173 + 174 X<> 25 175 RCL 24 176 + 177 X<> 25 178 FS? 01 179 * 180 RCL IND 25 181 + 182 FS? 01 183 GTO 01 184 R↑ 185 RCL 20 186 / 187 / ;_________________ 188 ◆LBL 01 189 FRC ; Analyze sum 190 R↑ 191 * 192 INT 193 4 194 X<>Y 195 FS? 00 196 GTO 01 197 X>Y? 198 RTN 199 GTO 02 200 ◆LBL 01 201 5 ; Analyze player 202 / 203 "YOU WIN" 204 X=Y? 205 PROMPT ; Player wins 206 FRC 207 X≠0? 208 RTN 209 LASTX 210 ◆LBL 02 ;_________________ 211 RCL 17 ; Test Tactical status 212 X>Y? 213 RTN 214 X<>Y 215 SF 02 216 STO 17 217 FC? 00 218 SF 03 219 RCL 18 220 STO 16 221 RTN ;_________________ 222 ◆LBL 21 223 1 224 RCL 22 225 GTO 01 226 ◆LBL 22 227 4 228 RCL 21 229 GTO 01 230 ◆LBL 23 231 5 232 ENTER↑ 233 0 234 GTO 01 235 ◆LBL 24 236 3 237 ENTER↑ 238 GTO 01 239 ◆LBL 25 240 SF 01 241 0 242 RCL 23 243 ◆LBL 01 ; Tactical play 244 STO 25 245 RDN 246 STO 24 247 1 E2 248 ENTER↑ 249 1 E8 250 FS? 0 251 X<>Y 252 FS? 01 253 STO 20 254 RCL 20 255 ◆LBL 05 ;_________________ 256 XEQ 19 257 X<> 25 ; Find move 258 RCL 24 259 + 260 X<> 25 261 1 E-2 262 FS? 00 263 1/X 264 RCL 20 265 FS? 01 266 * 267 GTO 05 ;_________________ 268 ◆LBL 20 269 16 270 STO 20 ; Strategic play 271 4 272 STO 25 273 1 274 STO 24 275 XEQ 07 276 2 277 XEQ 07 278 3 279 XEQ 07 280 0 281 XEQ 08 282 RCL 22 283 4 284 STO 24 285 * 286 STO 23 287 16 288 STO 20 289 1 290 XEQ 08 291 2 292 XEQ 08 293 3 294 XEQ 08 295 0 296 XEQ 08 297 RCL 22 298 RCL 23 299 + 300 STO 25 ;_________________ 301 ◆LBL 09 ; Find move 302 RCL IND 25 303 RCL 24 304 X<=Y? 305 GTO 01 306 RCL 25 307 2 308 / 309 FRC 310 X=0? 311 GTO 02 312 GTO 03 313 ◆LBL 01 ;_________________ 314 RCL 25 ; Reset reg. # 315 + 316 16 317 X>Y? 318 CLX 319 - 320 STO 25 321 GTO 09 322 ◆LBL 08 ;_________________ 323 STO 25 324 ◆LBL 07 ; Find total moves 325 RCL IND 25 326 X<> 25 327 RCL 24 328 + 329 X<> 25 330 RCL IND 25 331 + 332 X<> 25 333 RCL 24 334 + 335 X<> 25 336 RCL IND 25 337 + 338 X<> 25 339 RCL 24 340 + 341 X<> 25 342 RCL IND 25 343 + 344 X<> 25 345 RCL 24 346 + 347 X<> 25 348 INT 349 RCL 20 350 X<=Y? 351 RTN 352 RDN 353 STO 20 354 RDN 355 STO 22 356 RTN 357 ◆LBL 02 358 1 E2 ; Find empty space 359 XEQ 19 360 1 E4 361 XEQ 19 362 1 E8 363 XEQ 19 364 ◆LBL 03 365 1 E6 366 XEQ 19 367 1 E4 368 XEQ 19 369 1 E2 370 XEQ 19 371 1 E8 372 ◆LBL 19 373 STO 20 374 RCL IND 25 ; Check/store move 375 * 376 INT 377 1 E2 378 / 379 FRC 380 X≠0? 381 RTN 382 RCL 20 383 1/X 384 ST+ IND 25 385 LOG 386 2 387 / 388 5 389 + 390 RCL 25 391 4 392 / 393 INT 394 LASTX 395 FRC 396 4 397 * 398 1 399 ST+ IND 25 400 + 401 X<>Y 402 1 403 + 404 10 ; Place XYZ form 405 * 406 + 407 10 408 * 409 + 410 CLA 411 ARCL X 412 1 E3 413 / 414 FS?C 02 415 GTO 01 416 STO 18 417 RCL 17 418 3 419 X>Y? 420 GTO 01 421 FC? 03 422 GTO 01 423 "⊢, I WIN" 424 AVIEW ; 41C wins 425 GTO A 426 ◆LBL 01 427 ASTO X 428 "MY MOVE" 429 ARCL X 430 AVIEW 431 GTO A ; Get next player 432 .END. ; move
R00-R15 The Board R16 Test # R17 Tactic status R18 machine move R19 player move R20 used R21 Y-1 R22 Z-1 R23 Register # R24 Position Inc. R25 Used
00-03 Used
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