Pas6502 example unit usage

program joyTest;
uses
  c64_vic,c64_joy;

const
  SCREEN_ADDRESS   = 1024;
  SPR_PNTR_ADDRESS = SCREEN_ADDRESS + (2040 - 1024);
  SCREEN_ORIGIN_X  = 24;
  SCREEN_ORIGIN_Y  = 50;
  SPRITE_SPEED     = 2;
  VBLANK_LINE      = 251;

  sprite : array[0..62] of Byte = (
    0,127,0,1,255,192,3,255,224,3,231,224,
    7,217,240,7,223,240,7,217,240,3,231,224,
    3,255,224,3,255,224,2,255,160,1,127,64,
    1,62,64,0,156,128,0,156,128,0,73,0,0,73,0,
    0,62,0,0,62,0,0,62,0,0,28,0
  );

var
  i            : Byte;
  ram          : Integer absolute $0000;
  vic_spr_pntr : Integer absolute SPR_PNTR_ADDRESS;
begin
  //ENABLE SPRITE 2
  vic_spr_ena := vic_spr_ena or 4;

  //SPRITE 2 DATA FROM BLOCK 13
  vic_spr_pntr[2] := 13;

  // copy sprite data into block 13
  for i := 0 to Length(sprite) - 1 do begin
    ram[832 + i] := sprite[i];
  end;

  vic_spr2_x := SCREEN_ORIGIN_X + 255/2;
  vic_spr2_y := SCREEN_ORIGIN_Y + 200/2;

  disable_irq;

  while true do begin
    while vic_raster <> VBLANK_LINE do;

    read_joy2;

    if      input_dx = 1   then vic_spr2_x := vic_spr2_x + SPRITE_SPEED
    else if input_dx = 255 then vic_spr2_x := vic_spr2_x - SPRITE_SPEED;

    if      input_dy = 1   then vic_spr2_y := vic_spr2_y + SPRITE_SPEED
    else if input_dy = 255 then vic_spr2_y := vic_spr2_y - SPRITE_SPEED;
  end;
end.

//----------------------------------------------------------------------------
//c64_joy
//----------------------------------------------------------------------------
unit c64_joy;

uses
  joy,c64_cia;

procedure read_joy1;
var
  joy : Byte absolute cia1_prb; // port 1
begin
  reset_joy;

    if (joy and 1)  = 0 then input_dy  := input_dy - 1;
    if (joy and 2)  = 0 then input_dy  := input_dy + 1;
    if (joy and 4)  = 0 then input_dx  := input_dx - 1;
    if (joy and 8)  = 0 then input_dx  := input_dx + 1;
    if (joy and 16) = 0 then input_btn := input_btn + 1;
end;

procedure read_joy2;
var
  joy : Byte absolute cia1_pra; // port 2
begin
  reset_joy;

    if (joy and 1)  = 0 then input_dy  := input_dy - 1;
    if (joy and 2)  = 0 then input_dy  := input_dy + 1;
    if (joy and 4)  = 0 then input_dx  := input_dx - 1;
    if (joy and 8)  = 0 then input_dx  := input_dx + 1;
    if (joy and 16) = 0 then input_btn := input_btn + 1;
end;

procedure read_joy1and2;
var
  joy1 : Byte absolute cia1_prb; // port 1
  joy2 : Byte absolute cia1_pra; // port 2
  joy  : Byte;
begin
  reset_joy;

  joy := joy1 and joy2;

    if (joy and 1)  = 0 then input_dy  := input_dy - 1;
    if (joy and 2)  = 0 then input_dy  := input_dy + 1;
    if (joy and 4)  = 0 then input_dx  := input_dx - 1;
    if (joy and 8)  = 0 then input_dx  := input_dx + 1;
    if (joy and 16) = 0 then input_btn := input_btn + 1;
end;
//----------------------------------------------------------------------------
//joy
//----------------------------------------------------------------------------
unit joy;

var
  // Horizontal movement: -1 for left, 1 for right
  input_dx  : Byte;
  // Vertical movement: -1 for up, 1 for down
  input_dy  : Byte;

  // Main button: 1 pressed, 0 not pressed
  input_btn : Byte;

procedure reset_joy;
begin
  input_dx  := 0;
  input_dy  := 0;
  input_btn := 0;
end;
//----------------------------------------------------------------------------
//c64_cia
//----------------------------------------------------------------------------
unit c64_cia;

//   CIA1
var
  cia1_pra       : byte absolute $DC00;
  cia1_prb       : byte absolute $DC01;
  cia1_ddra      : byte absolute $DC02;
  cia1_ddrb      : byte absolute $DC03;
  cia2_pra       : byte absolute $DD00;
  cia2_prb       : byte absolute $DD01;
  cia2_ddra      : byte absolute $DD02;
  cia2_ddrb      : byte absolute $DD03;

//----------------------------------------------------------------------------
//c64_vic
//----------------------------------------------------------------------------
unit c64_vic;
//   VIC-II
var
  vic_spr0_x     : byte absolute $D000;
  vic_spr0_y     : byte absolute $D001;
  vic_spr1_x     : byte absolute $D002;
  vic_spr1_y     : byte absolute $D003;
  vic_spr2_x     : byte absolute $D004;
  vic_spr2_y     : byte absolute $D005;
  vic_spr3_x     : byte absolute $D006;
  vic_spr3_y     : byte absolute $D007;
  vic_spr4_x     : byte absolute $D008;
  vic_spr4_y     : byte absolute $D009;
  vic_spr5_x     : byte absolute $D00A;
  vic_spr5_y     : byte absolute $D00B;
  vic_spr6_x     : byte absolute $D00C;
  vic_spr6_y     : byte absolute $D00D;
  vic_spr7_x     : byte absolute $D00E;
  vic_spr7_y     : byte absolute $D00F;
  vic_spr_hi_x   : byte absolute $D010;
  vic_cr1        : byte absolute $D011;
  vic_raster     : byte absolute $D012;
  vic_lp_x       : byte absolute $D013;
  vic_lp_y       : byte absolute $D014;
  vic_spr_ena    : byte absolute $D015;
  vic_cr2        : byte absolute $D016;
  vic_spr_exp_y  : byte absolute $D017;
  vic_mem        : byte absolute $D018;
  vic_irq        : byte absolute $D019;
  vic_irq_ena    : byte absolute $D01A;
  vic_spr_dp     : byte absolute $D01B;
  vic_spr_mcolor : byte absolute $D01C;
  vic_spr_exp_x  : byte absolute $D01D;
  vic_spr_ss_col : byte absolute $D01E;
  vic_spr_sd_col : byte absolute $D01F;
  vic_border     : byte absolute $D020;
  vic_bg_color0  : byte absolute $D021;
  vic_bg_color1  : byte absolute $D022;
  vic_bg_color2  : byte absolute $D023;
  vic_bg_color3  : byte absolute $D024;
  vic_spr_color1 : byte absolute $D025;
  vic_spr_color2 : byte absolute $D026;
  vic_spr0_color : byte absolute $D027;
  vic_spr1_color : byte absolute $D028;
  vic_spr2_color : byte absolute $D029;
  vic_spr3_color : byte absolute $D02A;
  vic_spr4_color : byte absolute $D02B;
  vic_spr5_color : byte absolute $D02C;
  vic_spr6_color : byte absolute $D02D;
  vic_spr7_color : byte absolute $D02E;

  // other way of accessing sprite coord/color; array
  vic_spr_coord  : byte absolute $D000; // array of 8 x (x,y)
  vic_spr_color  : byte absolute $D027; // array of 8

const
  black       = 0;
  white       = 1;
  red         = 2;
  cyan        = 3;
  purple      = 4;
  green       = 5;
  blue        = 6;
  yellow      = 7;
  orange      = 8;
  brown       = 9;
  light_red   = 10;
  dark_grey   = 11;
  dark_gray   = 11;
  medium_grey = 12;
  medium_gray = 12;
  light_green = 13;
  light_blue  = 14;
  light_grey  = 15;
  light_gray  = 15;

procedure vic_set_scroll(xscroll,yscroll : Byte); assembler;
// this routine sets the hardware x and y scroll values
// from xscroll & yscroll respectively
asm
  lda vic_cr1
  and #$f8
  ora yscroll
  sta vic_cr1
  lda vic_cr2
  and #$f8
  ora xscroll
  sta vic_cr2
end;