$01/1: 6510 On-chip 8-bit Input/Output Register +----------+---------------------------------------------------+ | Bits 7-6 | Undefined | | Bit 5 | Cassette Motor Control | | | 0 = ON, 1 = OFF | | Bit 4 | Cassette Switch Sense: 1 = Switch Closed | | Bit 3 | Cassette Data Output Line | | Bit 2 | /CHAREN Signal (0=Swith Char. ROM In) | | Bit 1 | /HIRAM Signal (0=Switch Kernal ROM Out) | | Bit 0 | /LORAM Signal (0=Switch BASIC ROM Out) | +----------+---------------------------------------------------+ Default Value is $37/55. Flash_8 only: +--------+-----------------------------------------------------+ | Bit 7 | 1 = 1 Mhz, 0 = 8 Mhz (if DIP1 closed) | | Bit 6 | (?) | +--------+-----------------------------------------------------+ Default Value is $37/55.