andrewstellman

COBOL Terminal Cursor Control Demo

This is a small experimental COBOL project I built to learn a little bit about COBOL. The goal was simple: see if COBOL could support basic interactive console behavior—specifically, moving an asterisk around the screen using the W/A/S/D keys.

It uses raw ANSI escape sequences for cursor control and a small C helper to handle non-blocking keyboard input (so the user doesn't have to press Enter). The original version got stuck in a classic AI rehash loop—ChatGPT kept giving plausible but ineffective tweaks. I revisited it later using the five Sens-AI habits (Context, Research, Problem Framing, Refining, and Critical Thinking), and that broke the loop and got everything working.

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🔧 How to Build and Run

andrewstellman

Console.CursorVisible = false;
Console.Clear();

// Get console dimensions
int width = Console.WindowWidth;
int height = Console.WindowHeight;

// Center point of the pinwheel
int centerX = width / 2;
int centerY = height / 2;

andrewstellman

List<Particle> particles = new List<Particle>();
int width = Math.Max(20, Console.WindowWidth - 1);
int height = Math.Max(10, Console.WindowHeight - 1);

Console.CursorVisible = false;
for (int i = 0; i < 40; i++)
    particles.Add(new Particle(Random.Shared.Next(width), Random.Shared.Next(height)));

while (!Console.KeyAvailable)
{

andrewstellman

List<Particle> particles = new List<Particle>();
int width = Math.Max(20, Console.WindowWidth - 1);
int height = Math.Max(10, Console.WindowHeight - 1);

Console.CursorVisible = false;
for (int i = 0; i < 40; i++) // More particles for better visibility
    particles.Add(new Particle(Random.Shared.Next(width), Random.Shared.Next(height)));

while (!Console.KeyAvailable)
{

andrewstellman

// Parse command line arguments for width, height, density, and delay
var width = args?.Length > 0 && int.TryParse(args[0], out int w) && w > 0 ? w : 70;
var height = args?.Length > 1 && int.TryParse(args[1], out int h) && h > 0 ? h : 30;
var density = args?.Length > 2 && double.TryParse(args[2], out double d) && d > 0 && d <= 1 ? d : 0.3;
var delay = args?.Length > 3 && int.TryParse(args[3], out int ms) && ms >= 0 ? ms : 100;

// Initialize the grid with random cells
var grid = new bool[height, width];

// Fill cells randomly based on density parameter

andrewstellman

// Parse command line arguments for width, height, density, and frames
var width = args?.Length > 0 && int.TryParse(args[0], out int w) && w > 0 ? w : 70;
var height = args?.Length > 1 && int.TryParse(args[1], out int h) && h > 0 ? h : 30;
var density = args?.Length > 2 && double.TryParse(args[2], out double d) && d > 0 && d <= 1 ? d : 0.3;
var frames = args?.Length > 3 && int.TryParse(args[3], out int f) && f > 0 ? f : 500;

// Initialize the grid with random cells
var grid = new bool[height, width];
var random = new Random();

andrewstellman

// Parse command line arguments for width, height, density, and frames
var width = args?.Length > 0 && int.TryParse(args[0], out int w) && w > 0 ? w : 70;
var height = args?.Length > 1 && int.TryParse(args[1], out int h) && h > 0 ? h : 30;
var density = args?.Length > 2 && double.TryParse(args[2], out double d) && d > 0 && d <= 1 ? d : 0.3;
var frames = args?.Length > 3 && int.TryParse(args[3], out int f) && f > 0 ? f : 500;

// Initialize the grid with random cells
var grid = new bool[height, width];
var random = new Random();

andrewstellman

// Parse command line arguments for width, height, density, and frames
int width = args?.Length > 0 && int.TryParse(args[0], out int w) && w > 0 ? w : 70;
int height = args?.Length > 1 && int.TryParse(args[1], out int h) && h > 0 ? h : 30;
double density = args?.Length > 2 && double.TryParse(args[2], out double d) && d > 0 && d <= 1 ? d : 0.3;
int frames = args?.Length > 3 && int.TryParse(args[3], out int f) && f > 0 ? f : 500;

// Initialize the grid with random cells
bool[,] grid = new bool[height, width];
Random random = new Random();

andrewstellman

// Parse command line arguments for width, height, frames, and maxIterations
int width = 80; // Default width
int height = 40; // Default height
int frames = 100; // Default number of frames
int maxIterations = 100; // Default max iterations

// Check if args is not null
if (args != null)
{
    // Parse width if provided

andrewstellman

int width = 80; // Default width
if (args != null && args.Length > 0)
{
    if (int.TryParse(args[0], out int parsedWidth) && parsedWidth > 0)
    {
        width = parsedWidth;
    }
}
int height = width / 2;
double xMin = -2.0;