GA-EX58-UD3R: Serial Port

A cording to the manual the COMA header can provide one serial port
via an optional COM port cable. Where can I get such a cable? I am
living in Europe (Switzerland).

Thanks in advance

Walt Gallus

Walt Gallus wrote:
A cording to the manual the COMA header can provide one serial port via
an optional COM port cable. Where can I get such a cable? I am living in
Europe (Switzerland).

Thanks in advance

Walt Gallus

There are at least two standards for the adapter cable. In the
past, these pages provided some info.

AT-EVEREX
http://www.pccables.com/07120.htm

DTK (as seen on Intel D845PT)
http://www.pccables.com/07121.htm

Using this reference, we can compare.

http://www.frontx.com/cpx102_2.html ( purchase here http://www.frontx.com/order2.html )

"For all Asus motherboards, you can use our V1 cable.

1. CD - carrier detect
2. RXD - receive data
3. TXD - transmit data
4. DTR - data terminal ready
5. GND - system ground
6. DSR - data set ready
7. RTS - request to send
8. CTS - clear to send
9. RI - ring indicator"

So it would appear your Gigabyte board uses the same cable
as an Asus motherboard would use.

http://home.att.net/~Tom.Horsley/p4c800e.html

"... I definitely determined that the P4C800-E COM2 header needs an
AT-Everex-Intel style IDC-10 to DB-9 cable (whew!)."

So my guess would be, you need the AT-EVEREX one, which on FrontX is
the V1 version.

If you can purchase them as cheaply as the PCCables versions, in
Switzerland, you could always buy one of each cable type, to be sure.
For the PCCables, the shipping costs are likely higher than the
product cost.

You could go to your favorite web site in Switzerland and look
for Everex or DTK, or even DB9, and try and find a reference to
such an adapter.

Paul

"Paul" wrote


"For all Asus motherboards, you can use our V1 cable.

1. CD - carrier detect
2. RXD - receive data
3. TXD - transmit data
4. DTR - data terminal ready
5. GND - system ground
6. DSR - data set ready
7. RTS - request to send
8. CTS - clear to send
9. RI - ring indicator"

So it would appear your Gigabyte board uses the same cable
as an Asus motherboard would use.

This is the pin assignment of my GA-EX58-UD3R

Pin No.
Definition

1
NDCD-

2
NSIN

3
NSOUT

4
NDTR-

5
GND

6
NDSR-

7
NRTS-

8
NCTS-

9
NRI-

10
No Pin


I cannot (I am a complete non-expert) compare both assignments
because the expression do not correspond. Can you tell which version
is correct for me?

Thanks in advance

Walt Gallus

Walt Gallus wrote:
"Paul" wrote


"For all Asus motherboards, you can use our V1 cable.

1. CD - carrier detect
2. RXD - receive data
3. TXD - transmit data
4. DTR - data terminal ready
5. GND - system ground
6. DSR - data set ready
7. RTS - request to send
8. CTS - clear to send
9. RI - ring indicator"

So it would appear your Gigabyte board uses the same cable
as an Asus motherboard would use.

This is the pin assignment of my GA-EX58-UD3R

Pin No.
Definition

1
NDCD-

2
NSIN

3
NSOUT

4
NDTR-

5
GND

6
NDSR-

7
NRTS-

8
NCTS-

9
NRI-

10
No Pin


I cannot (I am a complete non-expert) compare both assignments because
the expression do not correspond. Can you tell which version is correct
for me?

Thanks in advance

Walt Gallus

What the Gigabyte staff did, was just copy the signal names from their design
schematic, rather than using the common names (as you'd find on a pinout page).
RXD or receive data is the same thing as SIN or Serial input.
TXD or transmit data is the same thing as SOUT or Serial output.
They're the same table. And as near as I can tell, the table
is called "AT-EVEREX". It least the GND or ground, got the same name.

1. CD - carrier detect NDCD
2. RXD - receive data NSIN
3. TXD - transmit data NSOUT
4. DTR - data terminal ready NDTR
5. GND - system ground GND
6. DSR - data set ready NDSR
7. RTS - request to send NRTS
8. CTS - clear to send NCTS
9. RI - ring indicator NRI

The pins of the header, are labeled in the same order as the pinout
tables you'll find on the web, like this one.

http://www.interfacebus.com/RS232_Pinout.html

If you look at the AT-Everex example here, where they
show both connectors in the diagram, you'll see the wiring is
not in natural order for direct connection to the connector.

http://www.pccables.com/07120.htm

The tables give the impression the wiring is "straight thru",
but to achieve the necessary interconnect, the ribbon cable has
to be split in two, and wires soldered to the DB9. This is necessary,
as otherwise the wrong pins would get connected. It is partially
to do with the way the two connectors are numbered.

(The AT-Everex has to be made by soldering. Then slide up the plastic hood.)
http://www.pccables.com/images/07120a.jpg

*******

The DTK pinout (*not* for you), seems to use a more clever scheme, in that
a DB9 with IDT rear interface can be used, requiring no soldering.

The thing is, the ribbon cable wires have to be adjacent to the things
they're to be connected to. If we look at the DTK example:

http://www.pccables.com/07121.htm

Motherboard
Header

1 3 5 7 9
2 4 6 8 10

Ribbon cable numbering

1234567890

RS232 connector

1 2 3 4 5
6 7 8 9

You can see, that if you were to just connect up the wires, in the
order that they fall naturally, 1 goes to 1, 2 goes to 6, 3 goes to 2,
and so on. It reduces fabrication cost, if no soldering is required.
I believe the DTK pin ordering, allows a DB9 with ribbon cable (IDT)
thing on its rear. You can see an example here, where the wires are just
joined in the order that they fall into place.

http://www.rentron.com/Flash-Stick-Cable.htm

The connector on the right of this photo, uses IDT termination on
the back of the connector. That allows cables to be made with a
press, rather than requiring cheap labor to solder 9 wires to the
back of the DB9 and slide the insulating hood over the solder area.
The DTK should be cheaper to make.

http://www.rentron.com/images/Pict00051.jpg

Anyway, I hope that isn't too boring. Any time this question comes
up, I have to go back and review the available information again,
to make sure I got the wiring right. I think the one you want is
AT-Everex, based on the pinout table provided by Gigabyte. The AT-Everex
uses soldering and a partial cable twist, to make it look like the pinout
tables are linear and one to one. (The DTK solves the problem, by
using an entirely different signal name ordering, on the motherboard
header. Which is easy for the motherboard engineer to do. By doing it
the DTK way, the adapter cable should be cheaper to make. There
are no twists or cable cutting necessary on the DTK. Just press and ship.)

HTH,
Paul

"Paul" wrote

What the Gigabyte staff did, was just copy the signal names from
their design
schematic, rather than using the common names (as you'd find on a
pinout page).
(...)

Thank you very much, Paul, for these detailed and well documented
informations. I appreciate your effort although your arguments ask
somtimes too much of me. But if I get you right, you think I should
look for the AT-EVEREX Version 1. If this is true I am embarassed
because I cannot find a single supplier in Switzerland, not even in
Europe. Ordering such cheap an article in the United States does not
make much sense. So I am still looking for an reasonable solution.

Thanks and regards
Walt Gallus

"Walt Gallus" wrote

But if I get you right, you think I should look for the AT-EVEREX
Version 1. If this is true I am embarassed because I cannot find a
single supplier in Switzerland, not even in Europe.

Paul, do you think this is the cable a need:
http://www.reichelt.de/?ACTION=3;ART...62;PROVID=2402
with this pin assignment:
http://www.reichelt.de/?;ACTION=7;LA...52FA K661.pdf

Walt Gallus

Walt Gallus wrote:
"Walt Gallus" wrote

But if I get you right, you think I should look for the AT-EVEREX
Version 1. If this is true I am embarassed because I cannot find a
single supplier in Switzerland, not even in Europe.

Paul, do you think this is the cable a need:
http://www.reichelt.de/?ACTION=3;ART...62;PROVID=2402
with this pin assignment:
http://www.reichelt.de/?;ACTION=7;LA...52FA K661.pdf


Walt Gallus

If you look at the wiring table given in C610_AK661.pdf,
it is a DTK and is the wrong kind.

P1 1 6 2 7 3 8 4 9 5 DB9 end
P2 1 2 3 4 5 6 7 8 9 Header end

*******

I can see one with the 1:1 wiring table on Ebay. I think this
one is Everex.

http://cgi.ebay.de/Serielle-Slotblen...e m5191586929

Mainboard Pin 1 2 3 4 5 6 7 8 9
9-Pin Typ 1:1 1 2 3 4 5 6 7 8 9

You also have the option of building your own cable. Or, go
to a local computer store, and see if they can order one for
you.

Paul

"Paul" wrote

it is a DTK and is the wrong kind.

what a pity :-(

I can see one with the 1:1 wiring table on Ebay. I think this
one is Everex.

Thanks for your hint. It is not in my country but I'll try to order
it.

Walt Gallus