====== LC //e Card - Mac-side Interface ======

The card Appears in the Macintosh LC as a series of registers in the slot's I/O space.

Each has 16 bits of usable data in big-endian order.  Therefore the high byte is at the register+0 address, low byte at the register+1 address.

^  ^  Read  ^^  Write  ^^  ^
^  Register  ^  High  ^  Low  ^  High  ^  Low  ^ Notes ^
|  $00  |  Trap Code  ||  None  || 0 when not trapped, trap code otherwise |
|  $04  |  Trap Address  ||  None  || |
|  $08  |  Soft Switches  ||  None  || Apple II soft switch status |
|  $0C  |  Trap Data  |  Control Byte  |  Resume  |  Control Reg 1  |  |
|  $10  |  Main Memory Data  |  Aux Memory Data  |  Main Memory Data  |  Aux Memory Data  | Slinky interface to Apple II RAM |
|  $14  |  None?  ||  None?  || |
|  $18  |  Keyboard  |  Data Out  |  Keyboard  |  Data Out  | Data Out = data to return from trapped read |
|  $1C  |  Memory Address  ||  Memory Address  || Slinky interface to Apple II RAM |
|  $20  |  Control Reg 2  ||  Control Reg 3  || At least keyboard and reset (bit 15 = reset) |