Where exactly does the ISA bus begin in a computer?

I compared ISA nad PCMCIA pinouts and there a lot of ISA slot and connect wires to PCMCIA pins) would work? Or would some

I've been able to find the PCI and ISA card edge footprints

isa expansion slot I have managed to figure out that the bottom row of pins in the EISA riser card slot are for the 2 PCI bus card + 3 ISA breakout board

isa slot Figure 3 describes the pinouts for the full 16-bit ISA expansion slot, and Figure 4 shows how the additional pins are oriented in the expansion slot