There was NuBus, that did not have any adoption within i386. It was used by Apple and at least one Unix vendor. https://en.m.wikipedia.org/wiki/NuBus https://e

There was NuBus, that did not have any adoption within i386. It was used by Apple and at least one Unix vendor. https://en.m.wikipedia.org/wiki/NuBus https://en.m.wikipedia.org/wiki/NuBus SPARC also had sbus, but this is likely later than your window. https://en.m.wikipedia.org/wiki/SBus https://en.m.wikipedia.org/wiki/SBus