Certain older DELL Desktop models having the riser carts with 2 PCI horizontal slots can be found on EBAY, the resources vary as parts like that are getting scarce due to the newer other computers, and laptops, putting these nice servicable older Dells out to the scrapheap...not all of them ,few DELL Optiplexes survive-Im using a DELL 170L Optiplex as I type this reply, and it has the same IRQ Riser board issue with its 2 PCI slots... can get the ethernet pcy slot to work, but need also really need that 5500 PCI graphics card to work too! Seems to be a Jumper Setting on the motherboard in these OPTIPLEX 170L models for the password, -->anybody got a clear view PDF file schematic showing what any of the jumpers do, and how to add more IRQs for the XP 32 bit Dell Optiplex 170 L systems on these things?
Routing IRQ's is long since gone. There are no jumpers or Bios settings to change this. The FX5500 card likely does not work due to it being PCI 2.0 5v only card or unbuffered. Pentium 4 based systems REQUIRE PCI 2.2 or PCI 2.3 cards that work with 3.3v instead of 5v
and have 2 Keyways in the slot connector. Changing a Riser does not re route or assign IRQ's.
You may be able to free up resources by disabling the serial and parallel ports but that won't fix anything if the card draws too much power and or is not PCI 2.2 compatible.
BAD CARD with no PCI buffers.
BAD CARD WITH PCI BUFFERS BUT 5V ONLY