PCI to ISA bridge

Hy!
I hope having posted in the right group.
I'm a newbie Digital Designer and I would like to have further
information about
EPROM for PCI-to-ISA bridge, 'cause I've got to switch an ISA card to
PCI connector.
I found out Winbond (W83628F & W83629D) and ITE (IT8888F) kits for
this purpose,
I read their datasheets as their tentative schematics pusblished also
on
costronic.com site as I read "PCI System Architecture" as "ISA System
Architecture" books.
My doubt was the EPROM used for both solutions. I've got some ideas
about the EPROM: it's expansion ROM for positive decode for ISA side
of PCI-ISA chips; I also downloaded some Assembler code for a general
purpose expansion ROM for the same. I understood that Rumtime Code is
(or should be) permantly present in memory after boot. But there's
still something unrevealed...

My questions are:

"What runtime code should I write inside the EPROM?"
"Does anybody encountered the same problem and found a solution?"

Thanks in advance