Macintosh Portable Data Interface
Pin Pin Name Definition
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1 /Modem_Power System power status
2 Ground Ground
3 /RTS Request to send
4 /DCD Data Carrier Detect
5 RxD Receive data
6 /CTS Clear to send
7 Modem_sound Analog sound output
8 TxD Transmit data
9 /RI_EXT Ring indicator
10 -5 VDC Power (switchable)
11 +5 VDC Power (unswitched)
12 /DTR Data terminal ready
13 V1 Sound volume control bit (Least significant)
14 V3 Sound volume control bit (Most significant)
15 V2 Sound volume control bit (Middle significant)
16 /Modem_Ins Modem installed
17 /Modem_Busy Modem busy
18 MS_Enable Modem sound enable