DB-9 to DB-9, crossover
DB-9 DB-9
M / F M / F
-------- --------
1 -------+-------4 (1 and 6 connected to 4
6 -------+
2 --------------- 3 (2 connected to 3)
3 --------------- 2 (3 connected to 2)
4 -------+------ 1 (4 connected to 1 and 6)
+------ 6
5 ------------- 5 (5 connected to 5)
7 --------------- 8 (7 connected to 8)
--------------- 7 (8 connected to 7)
5 CTS ------------ CTS 5