That won't really help AFAICT. You can get the interrupt, since all slots are ORed into /SLOTIRQ. The point of the VIA2 register is to decode which slot had the interrupt. If your card interrupts and you send it to the RBV video interrupt, that's telling the processor the RBV video interrupted, which isn't what you want. What you need is for the corresponding bit in the emulated VIA2's register A (I think this is RBV register C?) to indicate your desired slot had an interrupt. /IRQ0-3 from the 030 PDS correspond to slots 9, A, B, and E, which correspond to bits 0, 1, 2, and 5 of the second VIA's register A. So you somehow need to get bits 3 and 4 of that register to correspond to slot C and D /IRQ lines. What I'm saying is in the SE/30 these correspond to physical (and available) pins on VIA2, AFAICT. On the IIsi, I'm not sure these pins exist. Without the appropriate bit being set in that register, you don't get proper interrupt routing in software. It is possible to either modify SlotMgr or some other hack to alter the routing to do what you want, but that has changed from a pure hardware mod into needing drivers and/or possibly a ROM modification.