In the 1980s IBM PCs would mainly use CGA and EGA graphics cards to display color graphics. The corresponding monitors have often been already trashed, recycled or are simply broken. There are however still quite a few CRT monitors in the wild that were actually meant for home computers, like the C64, Amiga and similar. We have a look at the Philips CM8833-II, which sports a TTL RGB input, fitting for being driven by an EGA card.
Testing vintage mainboards, ISA cards or experimental homebrew hardware can be tedious and annoying when you have to deal with either a full blown PC case or a loose assembly of stuff on your desk. This 3D-printable test-bench by TechAmbrosia can help make this more organized and nice.