SNAKE
Змейка
The snake, arcade lineage from the mid 1970s; my own code, 2026
The reason the whole real-time side of this project exists, and since 16 August a real snake: a growing body, a bordered field, food that lands where chance puts it. The first version was fifty-six lines and had none of that. A snake needs a key read that does not stop and wait for Enter, and the dialect had a token for exactly that which my interpreter did not implement. SNAKE is the program that forced it. Everything on these disks that moves by itself came afterward.
- sectors
- 20-26
- source lines
- 128
- field
- 38 x 16
- step limit
- none
Run this disk · The image, 256,256 bytes
The token that was just sitting there
KEYIN, 0x25, was in the token table from the beginning, and the firmware names a handler address for it. Nothing in the recovered corpus ever calls it. Accounting software asks a question and waits for the answer; it has no use for a key that might not have been pressed. So the token stayed a name in a table for a long time. A snake cannot work that way. It has to keep moving whether or not you touched anything, which means the read has to be allowed to come back empty and let the program continue on the next line. Implementing that opened everything else.
Why the snake never turned
The first version steered nowhere. Press 4 and it went straight on into the wall, every time, exactly as if the key had not been pressed at all. KEYIN was writing both the character and its code, into both variable spaces, so a comparison like IF V10 = 52 was reading a slot that held a string as well as a number, and the string won. Every branch failed and the snake kept its heading until it hit something. The corpus decides the question: comparisons here are numeric, BAM3 line 1160 opens with ON V21+1, so the slot holds the code alone.
What is on the disk
Twenty by ten of playing area, held as bounds rather than drawn as a grid: the program prints one status line per step with the head, the apple and the score, and the wall exists only as four comparisons. There is no tail, so the only ways to lose are the wall and the forty step clock. The apple does not jump at random either. It walks a fixed pattern, five columns back and three rows on, wrapping when it leaves the field, because the dialect's random number atom is still undecoded and a constant is more honest than an invented encoding.
Not a find
Written in 2026. The snake is one of the oldest mechanics there is, common property since the arcade cabinets of the mid seventies, and this code is new and in Russian. No Soviet games disk was recovered by this project or by anyone else, and the qualifier belongs on the small disks as much as on the large ones: three sectors, one catalog entry, a header in sector 0, all of it in a format copied from the sides that really were read, wrapped around a program that is entirely mine.
What I checked
All checked: loaded, started, played to an outcome. SNAKE takes its keystrokes through it.key_source, a callable returning a key code or None, the same way TETRIS is driven.
What this does not show
What is tested is the emulator, not the hardware. The pace is still counted in program statements rather than seconds, so the game runs at whatever speed the host paces it to, exactly like TETRIS. Self collision is real but rare below a length of five, and the original fifty-six-line version, the one with no body at all, is what the v1.0 tag preserves. This page described that version until 16 August 2026; the shape of the story did not change, the snake did.
Where to read more
- SNAKE.bas, the source The 128-line rebuild; the original fifty-six lines, where the comparison against the key code first failed, live at the v1.0 tag
- One disk per program What each of the small disks holds and the state each one was left in after a run.
- The Iskra-226 manuals The Russian documentation for this machine, including a 261-page BASIC 02 language guide and the architecture and software reference.
The source
SNAKE.bas, 128 lines, assembled onto the image with iskra_asm.py
128 lines of BASIC
10 REM SNAKE 2 - REAL BODY 20 PRINT HEX(03) 22 PRINT AT(1,30);"* З М Е Й К А *" 24 PRINT AT(2,24);"4-ВЛЕВО 6-ВПРАВО 8-ВВЕРХ 2-ВНИЗ" 26 PRINT AT(1,55);"СЧЕТ:" 28 PRINT AT(1,61);"0" 30 V70 = 3 32 FOR V71 = 10 TO 49 34 PRINT ATV(V70,V71);"=" 36 NEXT V71 38 V70 = 20 40 FOR V71 = 10 TO 49 42 PRINT ATV(V70,V71);"=" 44 NEXT V71 46 V71 = 10 48 FOR V70 = 4 TO 19 50 PRINT ATV(V70,V71);"!" 52 NEXT V70 54 V71 = 49 56 FOR V70 = 4 TO 19 58 PRINT ATV(V70,V71);"!" 60 NEXT V70 62 V01 = 20 64 V02 = 11 66 V03 = 1 68 V04 = 0 70 V11 = 1 72 V12 = 1 74 V13 = 1 76 V14 = 0 78 A10(1) = 20 80 A11(1) = 11 82 V20 = 7 84 V20 = V20 * 38 86 V20 = V20 + 20 88 V20 = V20 - 10 90 A20(V20) = 1 92 PRINT ATV(V02,V01);"#" 94 GOSUB 800 96 GOTO 200 200 KEYIN V10, 210, 248 205 GOTO 248 210 IF V10 = 52 GOTO 220 212 IF V10 = 54 GOTO 226 214 IF V10 = 56 GOTO 232 216 IF V10 = 50 GOTO 238 218 GOTO 248 220 IF V03 = 1 GOTO 248 222 V03 = 0 - 1 223 V04 = 0 224 GOTO 248 226 IF V03 < 0 GOTO 248 227 IF V03 = 0 GOTO 229 228 GOTO 248 229 V03 = 1 230 V04 = 0 231 GOTO 248 232 IF V04 = 1 GOTO 248 234 V04 = 0 - 1 235 V03 = 0 236 GOTO 248 238 IF V04 < 0 GOTO 248 240 IF V04 = 0 GOTO 242 241 GOTO 248 242 V04 = 1 243 V03 = 0 248 FOR V90 = 1 TO 22 250 NEXT V90 260 V05 = V01 + V03 262 V06 = V02 + V04 270 IF V05 < 11 GOTO 900 272 IF V05 > 48 GOTO 900 274 IF V06 < 4 GOTO 900 276 IF V06 > 19 GOTO 900 280 V21 = V06 - 4 282 V21 = V21 * 38 284 V21 = V21 + V05 286 V21 = V21 - 10 288 IF A20(V21) = 1 GOTO 920 290 IF V05 <> V30 GOTO 350 292 IF V06 = V31 GOTO 400 350 V40 = A10(V12) 352 V41 = A11(V12) 354 V22 = V41 - 4 356 V22 = V22 * 38 358 V22 = V22 + V40 360 V22 = V22 - 10 362 A20(V22) = 0 364 PRINT ATV(V41,V40);" " 366 V12 = V12 + 1 368 IF V12 < 601 GOTO 420 370 V12 = 1 372 GOTO 420 400 V14 = V14 + 1 402 V13 = V13 + 1 404 PRINT AT(1,61);V14 406 GOSUB 800 420 V11 = V11 + 1 422 IF V11 < 601 GOTO 426 424 V11 = 1 426 A10(V11) = V05 428 A11(V11) = V06 430 A20(V21) = 1 432 V01 = V05 434 V02 = V06 436 PRINT ATV(V02,V01);"#" 440 GOTO 200 800 V30 = RND(1) 802 V30 = V30 * 38 804 V30 = INT(V30) 806 V30 = V30 + 11 808 V31 = RND(1) 810 V31 = V31 * 16 812 V31 = INT(V31) 814 V31 = V31 + 4 816 V32 = V31 - 4 818 V32 = V32 * 38 820 V32 = V32 + V30 822 V32 = V32 - 10 824 IF A20(V32) = 1 GOTO 800 826 PRINT ATV(V31,V30);"$" 828 RETURN 900 PRINT AT(22,26);"*** ВРЕЗАЛИСЬ В СТЕНУ ***" 910 GOTO 930 920 PRINT AT(22,27);"*** СЪЕЛИ СЕБЯ ***" 930 PRINT AT(23,29);"СЧЕТ:" 932 PRINT AT(23,35);V14 934 END
I wrote about this at the time
