rainer

hi everyone! i have a 4 switch woodgrain atari 2600 (working fine). in the case i joined a rasperry pi to the atari - enough space for 3 raspis ;-) as the atari runs with 5 volt after the voltage regulator (and the raspi runs on 5 volt too) i wonder if i could cancel the 9 volt and put the 5 volt directly on the pins of the regulator output. anyone done this before? any thoughts? greetings from austria rainer