Hi Al,

you need the Daystar-specific IIsi adapter, which has two slots, one for a NUBUS card and the other for the accelerator itself.  With a bit of searching you should be able to obtain one.  Be wary though that the IIsi has a weak power supply, so coupling accelerator + network card + max RAM + fast HD might bring it to its knees faster than you think; consider adding an external PSU if you really max out your machine.

JB