David, tu as raison pour la carte auxiliaire A20; qui donne les sons de synthèse et la voix. Mais la carte A6 à bien un convertisseur D/A. J'ai compris cela avec le texte suivant. Quand pense-tu?
A6 Sound board and A20 Auxiliary Sound board.
The A6 sound board has two 65C02 processors, a dual DAC (digital to analog converter), and an import port to receive signals from the CPU board. The sound board requires +5, +12 and -12 volts DC and a power-up reset signal from the CPU board (pressing sound board SW2 will give a manual reset). There are two 27256 EPROMs (the D1 and Y1 PROMs as Gottlieb calls them). This board is responsible for all the music and non-voice sounds.
The Auxiliary sound board A20 is the smaller of the two sounds board, and has a YM2151 sound generator and a MSM6295 sound/speech generator. Gets commands from the CPUs on the A6 sound board. This board has two 27020 or 27040 EPROMs (the A1 and A2 PROMs as Gottlieb calls them). This board is responsible for all the voice tracks. The game will work without this board, but of course there will be no speech.