What is the fine-grained topic of the following text: The Classic was very similar to its predecessor, as such that, due to limited technological advances, it used the same 9-inch (23 cm) monochrome CRT display, 512×342 pixel resolution, and its performance was hampered by the same 4 megabyte (MB) memory limit of the older Macintosh computers. Only return the topic.
Classic Macintosh computer specifications