A8N-E comm port inop.

Archived from groups: alt.comp.periphs.mainboard.asus (More info?)

I just built up a new system with an A8N-E, Athlon64 3800, &
WinXpProSr2. I cannot get the comm port to work. I use it for various
pieces of electronic hardware, and none can communicate with it.

As the simplest test, I've connected the machine to a single board
computer with a null modem cable. When I start Hyperterm, and try to
connect to the SBC, CPU usage goes to 100%, and my system is almost
totally unresponsive until I can get hyperterm to disconnect. If I move
the cable from this new machine to my old Win98 machine, all works fine.
The old computer and the SBC happily exchange information. I have
configured the com port (com1) on the new machine exactly the same as on
the old machine.

The only other com port on the new machine is a modem, which is assigned
to com4.

Any ideas?

Howard Delman
--
Delman Design
Digital design from conception to production
http://www.blueneptune.com/~delman

Archived from groups: alt.comp.periphs.mainboard.asus (More info?)

"Paul" <nospam@needed.com> wrote in message
news:nospam-0109052237060001@192.168.1.178...
> Also, I notice in the manual, that the A8N-E package
> does not come with a serial port adapter plate for a
> PCI slot. With third party adapter assemblies, there
> are two wiring patterns for the nine pins. The result
> is, not all adapter plates will work.
> Paul

My AN8-E (an early model) came with serial port adapter plate for a PCI slot
opening in the rear of the case. I have it hooked up to a 56 kbs US Robotics
modem that I occasionally use for faxing. It works perfectly.

It is described on page 1-27 of the user manual.

Maybe the OP did not hook it up properly to the motherboard header.

Archived from groups: alt.comp.periphs.mainboard.asus (More info?)

Paul wrote:
> In article <11hep3jprvqls7c@corp.supernews.com>, Howard Delman
> <delman@blueneptune.com> wrote:
>
>
>>I just built up a new system with an A8N-E, Athlon64 3800, &
>>WinXpProSr2. I cannot get the comm port to work. I use it for various
>>pieces of electronic hardware, and none can communicate with it.
>>
>>As the simplest test, I've connected the machine to a single board
>>computer with a null modem cable. When I start Hyperterm, and try to
>>connect to the SBC, CPU usage goes to 100%, and my system is almost
>>totally unresponsive until I can get hyperterm to disconnect. If I move
>>the cable from this new machine to my old Win98 machine, all works fine.
>> The old computer and the SBC happily exchange information. I have
>>configured the com port (com1) on the new machine exactly the same as on
>>the old machine.
>>
>>The only other com port on the new machine is a modem, which is assigned
>>to com4.
>>
>>Any ideas?
>>
>>Howard Delman
>
>
> On some other boards, Asus uses Texas Instruments GD75232
> RS-232 interface chips. These are old style chips, that
> run from +12V and -12V.
>
> http://www-s.ti.com/sc/ds/gd75232.pdf
>
> Is there any possibility that your -12V is out of whack?

I've had a 'scope on the Txd and Rxd lines, and they are wiggling at the
right baud rate, and their levels are reasonable. I know the port is
connected, and I know it is being written by software. But clearly...
something is severely messed up.

Howard

--
Delman Design
Digital design from conception to production
http://www.blueneptune.com/~delman

Archived from groups: alt.comp.periphs.mainboard.asus (More info?)

Paul wrote:
> In article <11hfrmjb0n7at12@corp.supernews.com>, Howard Delman
> <delman@blueneptune.com> wrote:
>
>
>>Paul wrote:
>>
>>>In article <11hep3jprvqls7c@corp.supernews.com>, Howard Delman
>>><delman@blueneptune.com> wrote:
>>>
>>>
>>>
>>>>I just built up a new system with an A8N-E, Athlon64 3800, &
>>>>WinXpProSr2. I cannot get the comm port to work. I use it for various
>>>>pieces of electronic hardware, and none can communicate with it.
>>>>
>>>>As the simplest test, I've connected the machine to a single board
>>>>computer with a null modem cable. When I start Hyperterm, and try to
>>>>connect to the SBC, CPU usage goes to 100%, and my system is almost
>>>>totally unresponsive until I can get hyperterm to disconnect. If I move
>>>>the cable from this new machine to my old Win98 machine, all works fine.
>>>>The old computer and the SBC happily exchange information. I have
>>>>configured the com port (com1) on the new machine exactly the same as on
>>>>the old machine.
>>>>
>>>>The only other com port on the new machine is a modem, which is assigned
>>>>to com4.
>>>>
>>>>Any ideas?
>>>>
>>>>Howard Delman
>>>
>>>
>>>On some other boards, Asus uses Texas Instruments GD75232
>>>RS-232 interface chips. These are old style chips, that
>>>run from +12V and -12V.
>>>
>>>http://www-s.ti.com/sc/ds/gd75232.pdf
>>>
>>>Is there any possibility that your -12V is out of whack?
>>
>>I've had a 'scope on the Txd and Rxd lines, and they are wiggling at the
>>right baud rate, and their levels are reasonable. I know the port is
>>connected, and I know it is being written by software. But clearly...
>>something is severely messed up.
>>
>>Howard
>
>
> Could it be a serial port interrupt happening over and over
> again ? Would a flow control RS-232 signal stuck in the
> wrong state do that ?
>
> Paul

I have flow control set to "none."

A flailing interrupt would certainly overwhelm the CPU, but that would
be a hardware fault. There is no data being sent, and the various
control lines are inactive, so there is nothing to generate an interrupt.

If you recall my test configuration, I have the comm port connected with
a null modem cable to an rs232 port on a single-board-computer. The SBC
is idling. There is nothing being sent between the machines. But
hyperterm is clearly being overwhelmed by something, and using 99% of
CPU capacity.

Since this is a brand new computer, it is possible that there really is
a hardware fault. But my experience suggests that is very very
unlikely. And I would dread having to rebuild the machine, and to
convince Asus to exchange my board.

Howard
--
Delman Design
Digital design from conception to production
http://www.blueneptune.com/~delman