My observations on this:
Aztech Soundblaster Pro clone:
mental.exe works with this card.
When the RESET bit is set, the 'data availible for read' flag is immediately cleared, the data itself stays the same as it was set to by the previous command. 100 microseconds later the 'data availible for read' flag is set and 0xAA can be read. This conforms to the soundblaster documentation.
At this point it makes no difference if the RESET bit is cleared or not.
Other clones: (82c929, CS4236)
mental.exe does not work.
When the RESET bit is set, the 'data availible for read' flag is immediately cleared, the data itself stays the same. Nothing else happens as long as the RESET bit is set.
Now, when we clear the RESET bit the 'data availible for read' flag is set immediately and 0xAA can be read from the data register.
It would be nice to know how original soundblasters (all mayor types) behave, if somebody who owns such volunteers I could make the test program availible.