The 8259 should be connected to 80186 int0 line. Don't know if that'll help at all though.
Tried using DEVWRITELINE("maincpu",i80186_cpu_device,int0_w) for the 8259, pretty much the same thing happens.
I found where the 8259 was mapped as the 4th, 5th and 6th words in the crash status are the ISR, IRR and IMR of the 8259 (for errors 26 (stray interrupt) and 27 (divide overflow). It also tells me that it is not touched at any point before then. It's not clear exactly what is triggering the interrupt.
