I have seen some boards not work in ISA slots. I did a little checking to refresh my memory, and the original standard ran the buss at 8.3Mhz and (naturally) had specific timing requirements for setup and hold of each signal line. Some cards are intolerant of deviation from these specs, so as later manufacturers started superceding it, those cards would not work.

But the position of LinearX is that the LMS board is compatible with any motherboard that has an ISA slot.