Logic analyzer isn’t a “must have” tool, especially for hobbyists. Most measurements of logic signals can be made with oscilloscope. But it doesn’t hurt to have one especially it costs cents literally.
One condition has to be met – your computer must be equipped with parallel port as this device is built for it. It uses only one chip – octal bus transceiver 74HC245N. Other is bunch of resistors and connectors. On PC side you will need a logic analyzer program that can be downloaded here. [Source]