Recreating Old Computer Art

int size = 100;
int cols = 7;
int rows = 5;
boolean light = false;
int a;
int b;


void setup() { 
  size (700, 500);
  smooth();
  noFill();
  noLoop();
  background (255);
}

void draw() {
  
    int[][] box = new int[cols][rows];
  for (int i = 0; i < cols; i++) {
    for (int j = 0; j < rows; j++) {
      box[i][j] = i;
      int a = i*100;
      int b = j*100;
      rect(a, b, 100, 100);
      println(i, j);
      int tx1 = int (random(i*100,i*100+50));
      int ty1 = int (random(j*100,j * 100 + 50));
      rect (tx1,ty1,50,50);
      int tx2 = int (random(i*100,i*100+50));
      int ty2 = int (random(j*100,j * 100 + 50));
      rect (tx2,ty2,30,30);
      int tx3 = int (random(i*100,i*100+50));
      int ty3 = int (random(j*100,j * 100 + 50));
      rect (tx3,ty3,20,20);
      int tx4 = int (random(i*100,i*100+50));
      int ty4 = int (random(j*100,j * 100 + 50));
      rect (tx4,ty4,10,10);
      int tx5 = int (random(i*100,i*100+40));
      int ty5 = int (random(j*100,j * 100 + 40));
      rect (tx5,ty5,60,60);
      int tx6 = int (random(i*100,i*100+30));
      int ty6 = int (random(j*100,j * 100 + 30));
      rect (tx6,ty6,70,70);
      int tx7 = int (random(i*100,i*100+20));
      int ty7 = int (random(j*100,j * 100 + 20));
      rect (tx7,ty7,80,80);
      int tx8 = int (random(i*100,i*100+10));
      int ty8 = int (random(j*100,j * 100 + 10));
      rect (tx8,ty8,90,90);
      int tx9 = int (random(i*100,i*100+50));
      int ty9 = int (random(j*100,j * 100 + 50));
      rect (tx9,ty9,40,40);
      int tx10 = int (random(i*100,i*100+50));
      int ty10 = int (random(j*100,j * 100 + 50));
      rect (tx10,ty10,45,45);

      
      
    //for 
 
 //if (frameCount > 0.1) {
  noLoop();
 //     //println(mouseX + " : " + mouseY);
 //   }
    }
}
}