There's a note in the Level 2 Service Reference manual that I came across, which may be saying that. Not certain it's saying exactly that, but it is concluding the same thing.

Apple3ServiceRefMan1982-10.pdf

Page 10.3, it says ("Peripheral connectors")

Quote
The Apple II emulation redefines a few of the pins on the connector and adds several new ones.

The most significant difference is that the interrupts will not be sent to the 6502 from the slots. In fact the IRQ (pin 30) is an input to the CPU so the card can't even determine if an interrupt is occurring. Thus Emulation mode runs without interrupts, period.

Last edited by paulhagstrom; 07/19/21 03:09 AM.