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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)