It has been a few years since I got this machine and I've been tinkering with it some more. In fact it got me back in to this hobby and may have even been the prompt to join up here a few years back. I've learned a few things, but still consider my knowledge to be extremely novice compared to the many smart people here. The goal was to upgrade this motherboard from the stock 12mhz to a 25mhz (or as fast as possible). Right now that's what I want to talk about, but we will talk ram at a later date. So far I've repaired the Dallas clock, then removed the 48mhz crystal oscillator, and replaced that with a socket. It appears that the crystal is 4 X the CPU speed. I've done tests with the following crystals that would all boot: 24mhz, 50mhz, and 100mhz, as well as a 80mhz that did not boot at all. Under the 24mhz and 50mhz things are quite stable. Under the 100mhz it under preforms from the expected 25mhz, and then has ram errors after 23 - 110 seconds of benchmarking. The 100mhz is acting like it is a 66mhz. Not sure if this is an issue with the crystal, or some other factor. Being that the 80mhz will not even post makes me wonder. I'm currently trying to get hold of some 64mhz crystals to try. Following the trace from the crystal, we come to a TIBPAL16R4 TTL type chip that has a spec sheet showing a 50mhz suggested maximum. Could this be the issue? Would putting something else in it's place possibly fix this? The TIBPAL16R6 series chips seem to have higher clocks from 52.5 - 100mhz MINIMUM, but I have no clue if any of these will drop in and work. They come in many flavors, and I do not know if I need internal feedback, external feedback, or no feedback versions, OR if any of this is even a valid hypothesis. Any suggestions or direction to pursue are greatly appreciated!

Thanks in advance,
TW