It seems I was mistaken about the 5200 logic board. It has been a long time since I clapped eyes on one of these, but on taking it out for a closer look at those lovely ram chips tonight, I discovered that the simms, as I had thought, were really dimms – meaning that this is not a 5200-series logic board. Looking further, it turned out to have a 120MHz CPU (which showed up for some reason the other night as a 75MHz chip in the system profiler!), which with dimms and a pci slot (how did I ever miss that, even in poor light in the garage?) means that the logic board is from a first revision 5400 - and cannot be either a 6360 or a 6400.
This changes my attitude to the modification a great deal. I like to keep my considerable collection of machines stock for the most part, but as this is not a piece of (s)crap, I think I'll keep it around rather than sell it on. While the board is rather temperamental, and so not necessarily the sort of thing you'd want to run in a mission-critical setting, I will likely want to experiment with it further.
Already, I have tried it briefly in my Color Classic, and got the CC to boot partly (to a question mark), but the video was mostly screwed up. I will no doubt have another go to see if I can get it to work in the CC one of these long winter nights, as there are jumpers on the extension board controlling, it appears, the video settings. Interesting possibilities are latent here, including, if one had the inclination and a willingness to undertake some de- and re-soldering, an easier way than usual to put a 6500 board in a Color Classic.
This changes my attitude to the modification a great deal. I like to keep my considerable collection of machines stock for the most part, but as this is not a piece of (s)crap, I think I'll keep it around rather than sell it on. While the board is rather temperamental, and so not necessarily the sort of thing you'd want to run in a mission-critical setting, I will likely want to experiment with it further.
Already, I have tried it briefly in my Color Classic, and got the CC to boot partly (to a question mark), but the video was mostly screwed up. I will no doubt have another go to see if I can get it to work in the CC one of these long winter nights, as there are jumpers on the extension board controlling, it appears, the video settings. Interesting possibilities are latent here, including, if one had the inclination and a willingness to undertake some de- and re-soldering, an easier way than usual to put a 6500 board in a Color Classic.