mdavis@pro-sol.cts.COM (Morgan Davis) (09/28/87)
This is the correct wiring diagram for the Apple IIGS Modem Port cable. Apple
is selling a printer cable for use with the modem port and it does not route
the correct DCD signal from the modem to the port. This can have bad effects
on *smart* software that calls the IIGS serial port firmware to test for
carrier status. Here's the correct pinout:
Date: Thu, 9 Jul 87 10:08:16 PDT
From: bblind (Bruce Lindmark)
DB-25 MINI DIN 8
2 <------------------------------< 3 TX-
3 >------------------------------> 5 RX-
6 >------------------------------> 2 DSR (handshake in)
20 <------------------------------< 1 DTR (handshake out)
8 >------------------------------> 7 DCD
7 ------------------------------- 4 SIG GND
|
-----> 8 RX+
Ground RX+ to prevent noise pick-up
RX+ is not needed for RS-232
6 TX+ no connect
|_|
6 7 8
3 4 5
1 2
pin locations for male mini din 8
In addition, change the Control Panel settings for the Modem Port as follows:
DCD Handshake: No
DSR/DTR Handshake: No
(the rest of the defaults are fine)
--Morgan Davis
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