For those who directed me to the Mystic overclocking modification instructions, thanks! I now have a successfully modified Mystic running at a mind-numbingly fast 40 mhz! It was my first soldering project, so visually the motherboard looks pretty inelegant. But who cares, it works!
THANKS AGAIN Y'ALL.
I was wondering, what CPU type did you overclock on your LC 575 logic board, the 68LC040 that usually comes with it (33 MHz / no FPU), the 68040 (33 MHz / with FPU, or the 68040-40 (40 MHz / with FPU)? Just wondering, any increase in heat, are the comm-ports still functional?
Full 68040, 33 mhz Purchased thru eBay at about $20. Heat sink that came with it affixed with thermal paste. Serial portd are functioning normally (we'll see how they behave when I find a 21.5 mhz oscillator). For some unknown reason, I've never been able to get ethernet working on this thing regardless of motherboard, card, slot, or modification, so I can't tell you if ethernet has been affected. 70 ns VRAM (courtesy of eBay and Olde Mac Milte) were necessary to avoid video artifacts.
MZ
Despite your self-criticism of your soldering, with a proper 040 CPU and the effort to get 70ns VRAM, it sounds like a thoroughly professionally-managed project to me! Congratulations on successfully completing the Mystic speed up. (43MHz is worth trying, though!)
Stuart
... for the compliment and the tips!