A system board 10-pin header connector IDC10 looks like this:
9 1 +---- ----+ | o o o o o | | o o o o o | +-----------+ 10 2
The two cable versions are DTK and AT/Everex/Intel
Here is a good post with ascii art:
http://hardware.mcse.ms/message235718-2.html
And one source of the DB-9 serial pinouts:
http://www.aggsoft.com/rs232-pinout-cable/serial-port-db9.htm
With the DTK assembly, the ribbon cable on either end should
come out the "side" of the connector (that is how cables
made with IDT method work).
With the Intel/Everex assembly, and the need to solder the wires to
the DB-9, it is possible the wire on the DB-9 will come out the end
of the assembly.
DTK Cable
DTK (xover) — pins "cross over": alternating top-to-bottom on the DB-9
| DB-9 | IDC-10 | Signal |
|---|---|---|
| Pin 1 | Pin 1 | CD |
| Pin 2 | Pin 3 | RxD |
| Pin 3 | Pin 5 | TxD |
| Pin 4 | Pin 7 | DTR |
| Pin 5 | Pin 9 | GND |
| Pin 6 | Pin 2 | DSR |
| Pin 7 | Pin 4 | RTS |
| Pin 8 | Pin 6 | CTS |
| Pin 9 | Pin 8 | RI |
The header pinouts needing DTK look like this:
Serial Port Pin Definitions
(COM1, COM2)
Pin Number Definition Pin Number Definition
1 DCD 6 CTS
2 DSR 7 DTR
3 Serial In 8 RI
4 RTS 9 Ground
5 Serial Out 10 NC
Intel Cable
Intel (sthru) — pins are "straight through": 1-1, 2-2, …, 9-9
| DB-9 | IDC-10 | Signal |
|---|---|---|
| Pin 1 | Pin 1 | CD |
| Pin 2 | Pin 2 | RxD |
| Pin 3 | Pin 3 | TxD |
| Pin 4 | Pin 4 | DTR |
| Pin 5 | Pin 5 | GND |
| Pin 6 | Pin 6 | DSR |
| Pin 7 | Pin 7 | RTS |
| Pin 8 | Pin 8 | CTS |
| Pin 9 | Pin 9 | RI |
The header pinouts needing Intel look like this:
Serial Port Pin Definitions
(COM1/COM2)
Pin # Definition Pin # Definition
1 CD 6 DSR
2 RD 7 RTS
3 TD 8 CTS
4 DTR 9 RI
5 Ground 10 NC