georgel wrote on 2021-09-09, 21:26:
For DOOM I discovered that if your AWE card is set to any other IRQ other than IRQ 5, this leads to instability. Still investigating. I guess any DMX sound engine game should be stable like this.
Are you sure it is "any other IRQ than IRQ5"? This indeed wouldn't make a lot of sense. On the other hand, specifically IRQ7 can be troublesome. ISA IRQs are handled by an Intel 8259 IRQ controller chip (integrated in the south bridge these days). When the 8259 receives an interrupt signal, it tells the processor that there is some interrupt to be handled. Some time later, the processor asks the interrupt controller what kind of interrupt the processor should execute. At that time, the 8259 searches for the highest-priority interrupt input that is still high (ignoring edge-triggered interrupt inputs they stayed high since the last time they were reported). If all inputs are low, the 8259 always request IRQ7. So if there is noise on any IRQ input creating short spurious pulses on that input, the result will be IRQ7.
If a game can not deal with spurious sound card IRQs (and I expect a lot of games can't), IRQ7 is a dangerous choice on systems where some spurious IRQs occur - with or without DOS32AWE, though.