Escape by Nick Shcherbyna

+----------------- PUR-80 BASIC GAME for Mattel Aquarius ----------- | (c) 2021 Nick Shcherbyna (Lviv, UA) [email protected] | +------------------------------------------------------------------- | Instructions / | | You are an alien imprisoned in the underground concentration camp known | as HANGAR-18. There are five levels with six floors each, patrolled by | bots. You have to avoid sentinels, otherwise mission will restart from | scratch. Fortunately bots are a bit dumb. Run as fast as possible and | climb up on the ladders using [O]-left, [P]-right, [A]-up and [Z]-down. | | Use real hardware or VirtualAquarius emulator: | https://www.zophar.net/download_file/32834 | | Use either Util->Paste to copy the BASIC source from file, or CLOAD the | tape image using File->Play Cassette File... Then RUN the game program. | +---------------------------------------------------------------- | Source Code Explained / |----------------------- | | Variables: | (X, Y) - Alien coordinates | Z - Alien address in VRAM | B - Saved character in place of alien | C - Character below of alien | (U, V) - Sentinel coordinates | W - Sentinel address in VRAM | D - Saved character in place of sentinel | E - Character below of sentinel | H - Ladder character code | M - Floor character code | S - Current level minus 1 | K - Shifted keycode | R - Random value | A$ - Beep character | | Lines: | 0 Init VRAM address (bottom right), randomize if (re)start, iterate all | screen characters. | 1 Init variables for procedural generation: L for ladder, F for floor. | 2 Calculate character and display it. Init alien and bot coordinates. | 3 Calculate bot VRAM addr. Check for game over condition and restart. | 4 Calculate alien VRAM addr. Put alien sprite, poll keyboard. | 5 Determine new alien position. Check whether level is completed. | 6 finalize new alien position. Start dealing with sentinel. | 7 Put sentinel sprite, determine new vertical position. | 8 Determine new horizontal position. Delay, restore characters in place | of sprites. | 9 Display message, end game if all levels completed. | +----------------------------------------------------------------- | Source Code Listing / |--------------------- | Note: Microsoft BASIC in Mattel Aquarius limits line of code to just 72 | characters, so the program below is effectively PUR-72 ;-) | 111111111122222222223333333333444444444455555555556666666666777 |123456789012345678901234567890123456789012345678901234567890123456789012 | | | | | | | | |0A=13248:FORY=0TO24:FORX=1TO38:Z=YAND3:R=RND(2*(S=0)+X+Y):L=PEEK(A+X+40) |1H=172:M=134:L=Z=1ANDL=MANDC<>HANDR<.2ORZ<>1ANDL=H:F=Z=LAND(C=32ORR<.98) |2C=32-102*(Y=0ORF)-140*L:POKEA+X,C:NEXTX:A=A-40:NEXTY:U=38:V=4:X=1:Y=6*V |3W=A+40*V+U:A$=CHR$(7):IFX=UANDY=VTHENPOKEW,209:?A$;A$;A$;CHR$(11);:RUN! |4Z=A+40*Y+X:B=PEEK(Z):C=PEEK(Z+40):POKEZ,146+(X+YAND1):K=PEEK(14346)-111 |5X=X+(X>1ANDK=0ANDC>32)-(X<38ANDK=1ANDC>32):Y=Y+(B=HANDK=-14):IFY=0THEN9 |6Y=Y-(C=32ORC=HANDK=11)::D=PEEK(W)::E=PEEK(W+40)::F=14+5*(U+VAND-(E>32)) |7POKEW,F-11*(E=32):L=(V<YANDE<>MORE=32)-(V>YANDD=H):REM(c)NickShcherbyna |8U=U+(L=0)*SGN(U-X):V=V-L:FORI=5*STO50:NEXT:POKEZ,B:POKEW,D:GOTO3ESCAPE! |9S=S+1:?CHR$(11);"CONGRATS! Level";S;"/5 completed!";A$;A$;A$:IFS<5THEN0 | +----------------------------------------------------------------