Chapter 2: Bomber

Typed in from the printed page, not yet checked against the author’s original — a difference here is our mistake, not theirs. Tell us and it goes in the errata.

// ---------------------------------------------------------------------// bomber.pas — Mad-Pascal, Chapter 2 of the Atari Legacy course// Wojciech "Bocianu" Bociański, Atari Legacy Issue 02//// !! TRANSCRIBED FROM THE PRINTED LISTING — NOT YET CONFIRMED BY THE// !! AUTHOR. Do not publish this file until Bocianu has sent the// !! original and downloads.verified has been flipped to true in// !! repo-src/resources/mad-pascal-02.toml.// ---------------------------------------------------------------------program bomber;uses atari, joystick;const    SCREEN_SIZE = 24*40;var    shipPos, bombPos, screenEdge: word;    ship: string[3] = ' <>'~;    GameOver: boolean = false;procedure DrawShip;var i: byte;begin    for i:=0 to 2 do        Poke(shipPos+i, Ord(ship[i+1]));end;procedure MoveShip;begin    Inc(shipPos);                                 // Move Ship    if shipPos = screenEdge then GameOver:=true;  // Check if Ship left screen    if Peek(shipPos+2) <> 0 then GameOver:=true;  // Check if Ship hit a buildingend;procedure MoveBomb;begin    Poke(bombPos, Ord(' '~));    Inc(bombPos, 40);    Poke(bombPos, Ord('v'~));end;procedure DropBomb;begin    bombPos := shipPos+3;end;procedure DrawBuildings;var col, row, height: byte;begin    for col:=0 to 39 do begin        height := 23-Random(12);        for row:=24 downto height do            Poke(savmsc+(row*40)+col, Ord('"'*~));    end;end;begin    FillChar(pointer(savmsc), SCREEN_SIZE, ' '~); // Fill screen with spaces    DrawBuildings;    shipPos := savmsc;                            // Set ship position to start of screen    screenEdge := savmsc + SCREEN_SIZE;           // Get length of screen    bombPos := screenEdge;                        // Bomb starts off screen    repeat        if rtclok3 and 3 = 0 then MoveShip;       // Move Ship        if bombPos < screenEdge then begin        // Check if Bomb is on Screen            if rtclok3 and 1 = 0 then MoveBomb;        end else            if strig0 = 0 then DropBomb;          // Drop Bomb        DrawShip;        Pause;    until GameOver;end.