A500+ 1MB expansion connected to an A500
 

Hello, would an A500+ 1MB expansion card work if connected to an A500? What would happen if it works? 512KB added to ChipRAM and 512KB added as SlowRAM? or the extra 512KB are simply ignored?

If you make no jumper changes then you would just get 512KB slow RAM. JP2 & _extick mod then you would get 512KB extra chip RAM (with 8372 or later Agnus of course).

You can't get the full 1MB without extra circuitry (Gary adapter).