A sample program to draw graphics on a command prompt or a dos window

grph3.c

#include <windows.h>

BOOL IsWindows9x()
{
	return (GetVersion() >= 0x80000000);
}

int main(int argc, char *argv[])
{
	HWND hWnd;
	HDC hdc;
	char szOldText[80], szId[32], szTemp[32];
	int x, y;
	
	GetConsoleTitle(szOldText, sizeof(szOldText));
	do {
		wsprintf(szId, "grph%08X", GetTickCount());
		SetConsoleTitle(szId);
		do {
			Sleep(100);
			GetConsoleTitle(szTemp, sizeof(szTemp));
		} while (lstrcmp(szId, szTemp));
		
		if (IsWindows9x()) {
			hWnd = FindWindowEx(NULL, NULL, "tty", szId);
		} else {
			hWnd = FindWindowEx(NULL, NULL, "ConsoleWindowClass", szId);
		}
	} while (hWnd == NULL);
	SetConsoleTitle(szOldText);
	if (IsWindows9x()) {
		hWnd = FindWindowEx(hWnd, NULL, "ttyGrab", NULL);
	}
	
	hdc = GetDC(hWnd);
	for(y = 0; y < 256; y++)
		for(x = 0; x < 256; x++)
			SetPixelV(hdc, x, y, RGB(x, y, (510 - x - y) / 2));
	ReleaseDC(hWnd, hdc);
	return 0;
}

Example on Win9x.