private int ReadBBus(int adr)
{
if (adr > 0x33 && adr < 0x40)
{
return(PPU.Read(adr));
}
if (adr >= 0x40 && adr < 0x80)
{
CatchUpApu();
return(APU.SpcWritePorts[adr & 0x3]);
}
if (adr == 0x80)
{
int val = _ram[_ramAdr++];
_ramAdr &= 0x1ffff;
return(val);
}
return(OpenBus);
}