Amiga Serial Port

25 pin D-sub male at the computer.

  Amiga 1000 only Other Amiga models
1 GND Frame Ground GND Frame Ground
2 TXD Transmit Data TXD Transmit Data
3 RXD Receive Data RXD Receive Data
4 RTS Request To Send RTS Request To Send
5 CTS Clear To Send CTS Clear To Send
6 DSR Data Set Ready DSR Data Set Ready
7 GND System Ground GND System Ground
8 CD Carrier Detect CD Carrier Detect
9 n/c   +12Vdc +12 Volt Power DC (20 mA)
10 n/c   -12Vdc -12 Volt Power DC (20 mA)
11 n/c   AUDO Audio out of Amiga
12 n/c   n/c  
13 n/c   n/c  
14 -5Vdc -5 Volt Power (50 mA) n/c   
15 AUDO Audio out of Amiga n/c   
16 AUDI Audio in to Amiga n/c   
17 EB Buffered Port Clock 716 kHz n/c  
18 /INT2 Interrupt line to Amiga AUDI Audio in to Amiga
19 n/c   n/c  
20 DTR Data Terminal Ready DTR Data Terminal Ready
21 +5Vdc +5 Volt Power (100 mA) n/c   
22 n/c   RI Ring Indicator
23 +12Vdc +12 Volt Power (50 mA) n/c   
24 /C2 3.58 MHz Clock n/c  
25 /RESB Buffered System Reset n/c  

Name Dir Std Notes
FGND   y Frame ground - do not tie to signal ground
TXD O y Transmit data
RXD I y Receive data
RTS O y Request to send
CTS I y Clear to send
DSR I y Data set ready
GND   y Signal ground - do not tie to frame ground
CD I y Carrier detect
-5Vdc   n 50 mA maximum
AUDO O n Audio output from left (channels 0,3) port, intended to send audio to the modem
AUDI I n Audio input to right (channels 1,2) port, intended to receive audio from the modem;
this input is mixed with the analog output the right. It is not digitized or used by the computer in any way.
DTR O y Data terminal ready
RI I y Ring indicator (A500/A2000) only shared with printer "select" signal
/RESB O n Amiga system reset

Warning: Pins on the RS-232 connector other than these standard ones described may be connected to power or other non-RS-232 standard signals. When making up RS-232 cables, connect only those pins actually used for a particular application. Avoid generic 25-connector "straight-thru" cables.

Source: Amiga Hardware Reference Manual