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) | ||