internal serial cable for COM2 - Asus AV8 Deluxe

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Wayne

I just added an internal serial cable for COM2 on my Asus A8V Deluxe.
There are two common but different ways that internal serial headers are
wired. This cable is 257237 from Frys Electronics, and is wired
straight-through, NOT crosswired. I believed that was correct? But it
doesnt work, so maybe not?

Anyone have any experience with that? Is straight or crossed correct?
 
Wayne said:
I just added an internal serial cable for COM2 on my Asus A8V Deluxe.
There are two common but different ways that internal serial headers are
wired. This cable is 257237 from Frys Electronics, and is wired
straight-through, NOT crosswired. I believed that was correct? But it
doesnt work, so maybe not?

Anyone have any experience with that? Is straight or crossed correct?

I'd say if it doesn't work, try the other one. :)

The serial ports in older Asus boards were wired straight
thru, but it's possible they changed formats at some point.

Are the pinouts in the manual?
 
I just added an internal serial cable for COM2 on my Asus A8V Deluxe.
There are two common but different ways that internal serial headers are
wired. This cable is 257237 from Frys Electronics, and is wired
straight-through, NOT crosswired. I believed that was correct? But it
doesnt work, so maybe not?

Anyone have any experience with that? Is straight or crossed correct?

Serial port 2 turned on on the bios?

Bill
 
I just added an internal serial cable for COM2 on my Asus A8V Deluxe.
There are two common but different ways that internal serial headers are
wired. This cable is 257237 from Frys Electronics, and is wired
straight-through, NOT crosswired. I believed that was correct? But it
doesnt work, so maybe not?

Anyone have any experience with that? Is straight or crossed correct?

The issue at the motherboard level, is whether the cable needed
is INTEL or DTK.

AT-EVEREX-INTEL pinout (likely the Asus way too)
http://www.pccables.com/07120.htm

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

One user's experiments - AT-EVEREX-INTEL on P4C800-E
http://home.att.net/~Tom.Horsley/p4c800e.html

Tying pin 2 and 3 together, should give you an echo.
(Assuming you used an INTEL cable on an INTEL header.)
If using a DTK cable on an INTEL header, you would
get a HyperTerminal echo by tying pin 2 to pin 6 (considering
the miswiring going on). You can try that if you don't
have a multimeter to verify the wiring.

******
At the equipment level, a piece of equipment can either
be DCE (Data Communications Equipment - the modem)
or DTE (Data Terminal Equipment - 80x24 terminal or a computer).
If connecting two computers together, you need a null modem
cable, which will convert one to the other. There is info
on interfaces and cables here:

http://www.cs.utk.edu/~shuford/terminal/serial_news.txt
******

There have also been some problems with serial ports on
S939 boards using 8712F Super I/O chip. I think the
first problem, doesn't include the use of an adapter
cable, meaning the problem is with the hardware.

A8N-E (using user's own adapter?)
http://groups.google.ca/group/alt.comp.periphs.mainboard.asus/browse_frm/thread/f099f55f924bc094
A8N-SLI (uses included COM cable)
http://groups.google.ca/group/alt.comp.periphs.mainboard.asus/browse_frm/thread/30fcc6a69281df2d

Fortunately, your board uses a Winbond chip, so it is not
likely to be the same problem as the two above. You also
have one motherboard COM1 port, to compare to the COM2
problem you are fighting.

HTH,
Paul
 
Paul, I knew there are the two common types. Question is which one?
I assumed straight-through was correct for the Asus A8V Deluxe, but it isnt
working, so maybe not? Problem might be something else, but I'm skeptical.

Bill, yes BIOS shows COM2 on at 2F8. But you're right, I never thought to
check it before. :)

Peter, yes, I need to find the other type to try. That is not real easy
locally. Many cables dont bother to even specify which type they are, I
guess magic makes it work out OK. Those that do may say Intel type (which I
assume implies crossed), may say straight through, or may say crossed. Then
the big problem is that Asus doesnt say which they need now. I thought
straight would be right, but my faith is shaken. The manual only shows the
pin 1 end. I dont find any mention of it online at Asus. I wish they had
provided this COM2 cable. I wish I still had a breakout box. :)

No one with an A8V Deluxe ever used COM2?
 
Paul, I knew there are the two common types. Question is which one?
I assumed straight-through was correct for the Asus A8V Deluxe, but it isnt
working, so maybe not? Problem might be something else, but I'm skeptical.

Bill, yes BIOS shows COM2 on at 2F8. But you're right, I never thought to
check it before. :)

Peter, yes, I need to find the other type to try. That is not real easy
locally. Many cables dont bother to even specify which type they are, I
guess magic makes it work out OK.

Do you have a cable on COM1? Is it a standard 9-pin connector?

Remove the connector from the the slot cover, or wherever it's attached.
The plastic "hood" will slide back, exposing the soldered wires.

You'll have one of these 2 patterns:
5.4.3.2.1
..9.8.7.6

9.7.5.3.1
..8.6.4.2

Pin 1 is always the same, so they either go right-to-left on top, then bottom,
or zig-zag up-down-up-down from right to left.

Make the new one the same way. 5 minute resoldering job.
 
Wayne said:
I just added an internal serial cable for COM2 on my Asus A8V Deluxe.
There are two common but different ways that internal serial headers
are wired. This cable is 257237 from Frys Electronics, and is wired
straight-through, NOT crosswired. I believed that was correct? But
it doesnt work, so maybe not?

Anyone have any experience with that? Is straight or crossed correct?

Hi Wayne!


If you mean the onboard serial ports, COM1 and COM2. You should take
Straight, not crossed, as it would from one COM to an Other COM
(Null-MoDem).

Watch out to connect the red marked wire to Pin 0 on the MB. If you
change the sides, the Serial Port won´t work. Like IDE Cables - Also
having Pin 0 (mostly, a red wire).

You can see Pin0 (sometimes marked as PIN1 instead of 0 - don´t worry
it´s the same) on the MB and probably also in the Manual of the MB.


Good Luck.




Best Regards,

Daniel Mandic
 
Paul, I knew there are the two common types. Question is which one?
I assumed straight-through was correct for the Asus A8V Deluxe, but it isnt
working, so maybe not? Problem might be something else, but I'm skeptical.

Bill, yes BIOS shows COM2 on at 2F8. But you're right, I never thought to
check it before. :)

Peter, yes, I need to find the other type to try. That is not real easy
locally. Many cables dont bother to even specify which type they are, I
guess magic makes it work out OK. Those that do may say Intel type (which I
assume implies crossed), may say straight through, or may say crossed. Then
the big problem is that Asus doesnt say which they need now. I thought
straight would be right, but my faith is shaken. The manual only shows the
pin 1 end. I dont find any mention of it online at Asus. I wish they had
provided this COM2 cable. I wish I still had a breakout box. :)

No one with an A8V Deluxe ever used COM2?

http://www.frontx.com/cpx102_2.html

"For all Asus motherboards, you can use our V1 cable. For other
brands of motherboard, you need to check the pin assignments
(more informations at the bottom of the page)."

Their pinout diagram looks straight thru to me - which is the
AT-Intel-Everex wiring. CPX102_2 looks like this:

http://www.pccables.com/07120.htm (AT-EVEREX-INTEL Version)

DB-9 IDC-10
Pin 1 Pin 1
Pin 2 Pin 2
Pin 3 Pin 3
Pin 4 Pin 4
Pin 5 Pin 5
Pin 6 Pin 6
Pin 7 Pin 7
Pin 8 Pin 8
Pin 9 Pin 9

To make a crossed cable, I would think you'd need room on one
end of the assembly, to cross the wires. Perhaps you can use that
as a visual cue. (If the connector housing on either end is
compact, then there isn't room for a crossover.)

As for the test I was attempting to get you to do, that is a
loopback test. If you had a straight cable on the Asus header,
shorting pin 2 to 3, then typing into a Hyperterminal session
pointed at that COM port, should give you two characters for
every one typed. Getting into Hyperterminal, and connecting
to that port, implies the "path" to that port is there in
software. Wiring pin 2 to pin 3 means TXD and RXD on that
port are connected to one another, and the resulting
echoed character should be visible to you in Hyperterminal.
That eliminates baud rate, start/stop problems from the equation.

If that test works, but you cannot connect to a modem, it could
be a baud rate mismatch, for example. It could also be a
flow control problem (i.e a busted wire in the cable assembly
could stop either a loopback test, or a test with a modem,
from working).

HTH,
Paul
 
News just in...

It has been explained to me that I am confusing the wiring.

I was wrong, and the wiring on the internal COM2 cable that I have is
NOT Straight-through. It is instead crossed, and it doesnt work on the AV8
Deluxe. I obviously need a straight-through cable, in agreement with
conventional wisdom for Asus (but not tested yet).

The crossed cable I bought didnt specify what it was (most dont), but after
opening the hood, the pinout of a cross-wired cable matches the actual
ordering of the DB9 pin arrangement, and the final result of a crossed cable
allows the ribbon to remain very flat and very orderly after wiring each
consecutive ribbon wire to the next closest pin, left to right, simply
ALTERNATING UPPER AND LOWER PIN ROWS in the same order as the ribbon cable.

This must be the only purpose of the crossed function, since extension
cables are otherwise always straight through. I superficially confused this
orderly straight wiring with a straight-through cable, but it is instead a
crosswired cable, designed to be very flat and orderly at the DB9.

A straight-through cable wiring is much more jumbled up at the DB9, having
to loop back to several pins on the other side, due to the DB9 pin numbering
scheme itself being jumbled, at least in any left-to-right sense like say a
ribbon cable is orderly.

I hope this can help someone else now, instead of confuse.
 
News just in...

It has been explained to me that I am confusing the wiring.

I was wrong, and the wiring on the internal COM2 cable that I have is
NOT Straight-through. It is instead crossed, and it doesnt work on the AV8
Deluxe. I obviously need a straight-through cable, in agreement with
conventional wisdom for Asus (but not tested yet).

The crossed cable I bought didnt specify what it was (most dont), but after
opening the hood, the pinout of a cross-wired cable matches the actual
ordering of the DB9 pin arrangement, and the final result of a crossed cable
allows the ribbon to remain very flat and very orderly after wiring each
consecutive ribbon wire to the next closest pin, left to right, simply
ALTERNATING UPPER AND LOWER PIN ROWS in the same order as the ribbon cable.

This must be the only purpose of the crossed function, since extension
cables are otherwise always straight through. I superficially confused this
orderly straight wiring with a straight-through cable, but it is instead a
crosswired cable, designed to be very flat and orderly at the DB9.

A straight-through cable wiring is much more jumbled up at the DB9, having
to loop back to several pins on the other side, due to the DB9 pin numbering
scheme itself being jumbled, at least in any left-to-right sense like say a
ribbon cable is orderly.

I hope this can help someone else now, instead of confuse.

"ALTERNATING UPPER AND LOWER PIN ROWS" - I think that is DTK.

I realize after thinking about it some more, that my cable
description terminology leaves a lot to be desired. "Crossed"
seems to lack precision :-)

My reference point in a cable assembly like this, is the
ribbon cable. The wires in the ribbon cable start with wire 1
being the one marked with some red color on the insulation.

The end of the ribbon cable assembly that plugs into the
motherboard, is an "insulation displacement technology" or
IDT connector. No solder is used - instead each wire is pushed
between two tiny posts, and the posts bites the wire. The
insulation on each wire is displaced. (This is the same method
used to make PATA (IDE) cables.) It has a 2x5 hole pattern,
with 0.1" spacing grid for the holes. When the linearly numbered
ribbon cable wires are connected to the IDT connector, the connector
pin numbering looks like this.

(when ribbon is compressed against a 2x5 header and
the other end is compressed against an IDT DB-9.
This is apparently DTK wiring pattern - not Asus)

1 3 5 7 9 12345678910 1 3 5 7 9
2 4 6 8 10 (ribbon cable) 2 4 6 8

ribbon number ribbon number
where it hits 2x5 where it hits DB-9 pin

In the above, if a DB-9 connector that uses IDT on its
backside, is connected to a ribbon cable, the wires go
to the nearest pin as you move left to right. This is,
apparently, the DTK wiring pattern. To using this crimping (mass
termination) method, the ribbon cable cannot randomly select
any pin on the connector at the other end. In North America,
this would be the cheapest way to make a cable, and would be
preferred from an assembly cost perspective.

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). A side view of a DTK
cable should look like this:

|X X| 2x5 \|X X|/ DB-9
| | | |
--------------------------------- side view DTK
[___] [___]

To make any other wiring pattern, requires a DB-9 connector with
solder terminations sticking out the back of the connector.

In the AT-Everex-Intel wiring, the 2x5 end of the cable is still
fastened by the IDT method. But, at the DB-9 end, the first
five sequential wires of the ribbon, are soldered to the top row
of DB-9 solder terminals. The next four sequential wires are
soldered to the bottom four terminals. The DB-9 shield ground
is established when the PCI bracket is screwed to the computer
chassis. Again, using only the "ribbon cable number" as the
reference numbering scheme, an Everex cable looks like this
(Asus style).

(when ribbon is compressed against a 2x5 header and
the other end is soldered to a soldertail DB-9.
This is apparently Everex wiring pattern used by Asus,
at least that is frontx.com's claim.)

1 3 5 7 9 12345678910 1 2 3 4 5
2 4 6 8 10 (ribbon cable) 6 7 8 9

ribbon number ribbon number as soldered
where it hits 2x5 to DB-9 pins

With the Everex assembly, and the need to solder the wires to
the DB-9, it is possible the wire on the DB-9 end, will come
out the end of the assembly, like this.

|X X| 2x5 \|X X|/ DB-9
| | | |
--------------------- | | side view Everex/Asus
[___] \ [___]
\ / <-- wire on end
\______/

Now, everyone knows that there are numbers printed next to
each pin, when looking into the end of a DB-9 connector.
The numbers you see printed on the end look like this, and
you'll need a magnifying glass to see them.

1 2 3 4 5
6 7 8 9

Those are the numbers you will see if consulting internet pinout
web pages, for example when wiring up null modem cables and the
like. I will switch to using those numbers in the "wiring
tables" below.

Now, a couple of web page examples.

**************************************************
This page sells an Everex/Asus cable. The information shown is
a "wiring table", in "from-to" format.

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

(Picture of how it is soldered - frontx V1 "Asus" cable
First five wires to top, next four wires to bottom)
http://www.frontx.com/cpx102_2_p4.gif

__________
/ \
| first five wires in ribbon
v to top row
-------------- | -----------
\ 1 2 3 4 5 / 12345 | 1 3 5 7 9 | Everex/Asus
\ 6 7 8 9 / 6789x | 2 4 6 8 x |
---------- | -----------
^ next four wires
| to bottom row
\________/


From DB-9 pin 1 to Header pin 1
From DB-9 pin 2 to Header pin 2
From DB-9 pin 3 to Header pin 3
From DB-9 pin 4 to Header pin 4
From DB-9 pin 5 to Header pin 5
From DB-9 pin 6 to Header pin 6
From DB-9 pin 7 to Header pin 7
From DB-9 pin 8 to Header pin 8
From DB-9 pin 9 to Header pin 9
**************************************************
This page sells a DTK cable (the one we don't want).

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

(Picture of how it is soldered - frontx V2 "non-Asus" cable
ALTERNATING up-down pattern)
http://www.frontx.com/cpx102_2b_p4.gif

Ribbon cable wire - wire 1 goes to pin 1, wire 2 goes to pin 6
| wire 3 goes to pin 2, wire 4 goes to pin 7.
| A natural for IDT press fit installation
| and side mounted cable exit, but could
v still be made by end-on soldering as labor
in Taiwan is cheap.
123456789
|||||||||
vvvvvvvvv
-------------- -----------
\ 1 2 3 4 5 / | 1 3 5 7 9 | DTK
\ 6 7 8 9 / | 2 4 6 8 x |
---------- -----------

From DB-9 pin 1 to Header pin 1
From DB-9 pin 2 to Header pin 3
From DB-9 pin 3 to Header pin 5
From DB-9 pin 4 to Header pin 7
From DB-9 pin 5 to Header pin 9
From DB-9 pin 6 to Header pin 2
From DB-9 pin 7 to Header pin 4
From DB-9 pin 8 to Header pin 6
From DB-9 pin 9 to Header pin 8
**************************************************

I haven't used the word "crossed" in this attempt, so
maybe this attempt will be clearer.

Refs:
http://home.att.net/~Tom.Horsley/p4c800e.html (Everex by experiment)
(Near very bottom of page "COMM & LPT" - shows an Everex wire table)
http://web.archive.org/web/20040604064344/http://www.jump.net/~lcs/kalle/rev3.htm
http://www.frontx.com/cpx102_2.html (Asus)
http://www.frontx.com/cpx102_2b.html (non-Asus)

Paul
 
As I document in my http://home.att.net/~Tom.Horsley/p4c800e.html web page,
there can be lots of confusion when talking about pin numbers and "straight
through". The actual official pin numbers in ascending order on a DB-9
connector go "longways", whereas the official pin numbers on the IDC-10
connector go "shortways", so when you are connecting things "straight
through" are you going from similar geometry to similar geometry, or are you
going from the same pin number to the same pin number?

My hypothesis is that this confusion is what led to the two different forms
of cable (but it could be something more techinal I suppose like different
kinds of cable building machines that find it more convenient to work one
way or the other).

The real mystery in all this is why the ASUS motherboard manuals document
every single header in excruciating detail pin by pin, EXCEPT the dad-gum
COM2 header? Why did they pick on COM2?
--email: (e-mail address removed) icbm: Delray Beach, FL |
<URL:http://home.att.net/~Tom.Horsley> Free Software and Politics <<==+
 
The real mystery in all this is why the ASUS motherboard manuals document
every single header in excruciating detail pin by pin, EXCEPT the dad-gum
COM2 header? Why did they pick on COM2?

I filled out the online form to ask Asus which cable for COM2,
and received a quick response, of one word: "Closed!"

Still very nice motherboards.
 
I filled out the online form to ask Asus which cable for COM2,
and received a quick response, of one word: "Closed!"

Still very nice motherboards.

Better to phone Asus tech support, and see if they can offer
a justification for not providing info on the header.
It is not like they'll be making a lot of money selling
adapters. It is hard to find an Asus adapter in any case.

Paul
 
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