Jofm5
It's so long since I had to look at this I bow to your greater knowledge.
I do recall the days of ISA / EISA cards when IRQs and I/O ports had to be specified - on the card (jumpers / switches) and the BIOS (reservations), and also in the OS.
The introduction of P&P spanned the demise of ISA and the introduction of PCI, and I will admit to some confusion now as to which required what, where and how!
At the same time, Win 95 introduced P&P at the OS level.
I recall being impressed that multiple devices could now "share" a single IRQ (usually 10, IIRC).
I also remember being infuriated by Win 9x's insistence on "managing" IRQ allocations, when faced with a mix of P&P and non-P&P devices - and eventually switching off P&P!
I do remember it being referred to as Plug and Pray.
But since then, I have not, to my knowledge, had a P&P related issue.
Are you referring to the BIOS level or the OS level - or both?
SD