My guess is, its highly proprietary, probably requires something more unique to the hardware of the older systems, not so much the OS.
Additionally, I don't think it would provide much cooling benefit as the PCMCIA area is usually isolated by plastic, to keep dust and dirt out of the greater system.
Several years ago when running W98 on laptops, I bought a little cooling fan that fit into the PCMCIA slot. It ran as long as it was pluged in. It worked on all (several Compaqs, IBMs, and Toshibas) running W98 and did an excellent job of coolin the innards.
It will not turn on in any of my XP laptops.
Thoughts?

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