I read Doug's post, and subsequent posts, and started to write a response that filled in on a few points. Such as, actual S-100 bus history. Or, why a "slot" isn't quite a bus, and the history of that. And, how IBM's PC bus isn't quite like MITS's Altair Bus - which wasn't quite "S-100". That became a lecture, and it's not useful or polite to post a lecture. So I created a Web page instead, and I'm posting a link to that, for those interested in a little more background. While it's my opinion, it's a technically informed one; some history can be argued of course. It's also on-the-fly and a bit rough. http://www.retrotechnology.com/herbs_stuff/bus_history.html The point relevant to this discussion, is to flesh-out some of the background that Doug references. I hope it informs his intended display. It's certainly a good idea, to display and describe general features of vintage computers. One of them is a bus architecture, or maybe the lack of one, why such things occur, and their consequences. My interest in S-100 architectures is certainly a consequence. Much of my Web site is devoted to S-100 computers. Others who have posted, have sites or interests in specific brands or architectures. I'm informed by their responses in my document. Thanks to all and I hope I have some useful considerations in my offline response. Regards Herb Johnson -- Herbert R. Johnson, New Jersey USA https://www.retrotechnology.com OR .net preserve, recover, restore 1970's computing email: hjohnson AT retrotechnology DOT com or try later herbjohnson AT comcast DOT net