These images were downloaded from http://www.javalemmings.com/plus4/programming/hardwaredocs.htm and http://www.javalemmings.com/plus4/images/prog/.
The image files were originally provided by Tibor Biczo as 24-bit JPEG images. William Levak reduced them to 16-colour GIF and improved the image quality. This HTML file and the thumbnails were provided by Marko Mäkelä.