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The back panel of all Power Macintosh models contain two I/O ports for serial telecommunication data. Both sockets accept 9-pin plugs, allowing either port to be independently programmed for asynchronous or synchronous communication formats up to 9600 bps. This includes AppleTalk and the full range of Apple GeoPort protocols.



9 pin Apple mini din connector at the end of the peripheral cable, from the front of the connector

Pin	Signal	Description
1	SCLK (out)	Reset pod or get pod attention
2	SCLK (in)	Serial clock from pod (up to 920 Kbit/sec.)
3	TxD-	Transmit -
4	GND	Ground
5	RxD-	Receive -
6	TxD+	Transmit +
7	Wake up / TxHS	Wake up CPU or do DMA handshake
8	RxD+	Receive +
9	+5V	Power to pod (350 mA maximum)