Jo22 wrote on 2022-11-22, 12:28:

From what I remember, it ran ISA at CPU speed - 12 MHz. […]
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From what I remember, it ran ISA at CPU speed - 12 MHz.

I mean: The AT-Bus (later known as ISA) was essentially identical with the 286 front side bus (FSB).

So it's possible that my PC ran ISA directly, synchronous with the CPU.
Sure, there's also the possibility that the chipset had decoupled it.

The first ISA 286 PC I had ran ISA at CPU clock, but whenever an actual on-bus ISA cycle was detected, the CPU was down-clocked from 12MHz to 8MHz. The mainboard documentation indicated a jumper to disable this speed matching logic, but stated that you must not do so.