-> -> How can SIO handle the port without an IRQ? Use polling?

-> It will; however, IIRC only if native OS/2 comm apps are using the
-> port.  Otherwise, you have to assign IRQs for DOS and Win64 comm

You're thinking of the DOS reflection IRQ provided by the vsio.sys
virtual device driver. The sio.sys physical device driver requires an
IRQ (possibly shared) for every port; it will not do polling.

I think Holger assumed that my IRQ 3 was a motherboard com port that
could be disabled in the BIOS.  That's not so; it's a PCI expansion card
that PCI assigns to IRQ 3, because there is no COM2 on the motherboard.

So I'm stuck with IRQ 3, like it or not. But as Mark said, sio2k may be
the problem.  I'll try again with SIO 1.60d.

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