serial port doesn't work

Call me old fashioned, but I still need traditional serial ports. I have three machines with Edgy Ubuntu, the serial port works out of the box on two of them (Compaq Deskpro and Compaq Armada 7800), but not on the third (HP Compaq NC6000 laptop). The NC6000 can do it with COM1 in Windows, though. I am pretty sure that defective hardware and cable problems can be excluded, and the "far side", i.e. the Deskpro, is ok as well.

Right now, I'm just connecting two machines with a null-modem cable. Can anyone help, please? Thanks.

Here is what I get:

{dirk@wanchai}[/home/dirk]ls -l /dev/ttyS*
crw-rw-rw- 1 dialout 4, 64 2006-11-28 03:27 /dev/ttyS0
crw-rw-rw- 1 dialout 4, 65 2006-11-28 03:27 /dev/ttyS1
crw-rw-rw- 1 dialout 4, 66 2006-11-28 03:27 /dev/ttyS2
crw-rw-rw- 1 dialout 4, 67 2006-11-28 03:27 /dev/ttyS3

{dirk@wanchai}[/home/dirk]setserial -a /dev/ttyS0
/dev/ttyS0: No such device

{dirk@wanchai}[/home/dirk]sudo setserial -a /dev/ttyS0
/dev/ttyS0, Line 0, UART: 16550A, Port: 0x03f8, IRQ: 4
Baud_base: 115200, close_delay: 50, divisor: 0
closing_wait: 3000
Flags: spd_normal skip_test

{dirk@wanchai}[/home/dirk]sudo setserial -g /dev/ttyS*
/dev/ttyS0, UART: 16550A, Port: 0x03f8, IRQ: 4
/dev/ttyS1, UART: unknown, Port: 0x02f8, IRQ: 3
/dev/ttyS2, UART: 16550A, Port: 0x03e8, IRQ: 4
/dev/ttyS3, UART: unknown, Port: 0x02e8, IRQ: 3

{dirk@wanchai}[/home/dirk]echo blahblah > /dev/ttyS0
/dev/ttyS0: No such device.

{dirk@wanchai}[/home/dirk]sudo echo blahblah > /dev/ttyS0
/dev/ttyS0: No such device.

{dirk@wanchai}[/home/dirk]dmesg | tail -3
[17204867.876000] ttyS0: LSR safety check engaged!
[17204885.488000] ttyS0: LSR safety check engaged!
[17204901.476000] ttyS0: LSR safety check engaged!
Can anyone help, please? Thanks.Call me old fashioned, but I still need traditional serial ports. I have three machines with Edgy Ubuntu, the serial port works out of the box on two of them (Compaq Deskpro and Compaq Armada 7800), but not on the third (HP Compaq NC6000 laptop). The NC6000 can do it with COM1 in Windows, though. I am pretty sure that defective hardware and cable problems can be excluded, and the "far side", i.e. the Deskpro, is ok as well.

Right now, I'm just connecting two machines with a null-modem cable. Here is what I get:

Quote:
{dirk@wanchai}[/home/dirk]ls -l /dev/ttyS*
crw-rw-rw- 1 dialout 4, 64 2006-11-28 03:27 /dev/ttyS0
crw-rw-rw- 1 dialout 4, 65 2006-11-28 03:27 /dev/ttyS1
crw-rw-rw- 1 dialout 4, 66 2006-11-28 03:27 /dev/ttyS2
crw-rw-rw- 1 dialout 4, 67 2006-11-28 03:27 /dev/ttyS3

{dirk@wanchai}[/home/dirk]setserial -a /dev/ttyS0
/dev/ttyS0: No such device

{dirk@wanchai}[/home/dirk]sudo setserial -a /dev/ttyS0
/dev/ttyS0, Line 0, UART: 16550A, Port: 0x03f8, IRQ: 4
Baud_base: 115200, close_delay: 50, divisor: 0
closing_wait: 3000
Flags: spd_normal skip_test

{dirk@wanchai}[/home/dirk]sudo setserial -g /dev/ttyS*
/dev/ttyS0, UART: 16550A, Port: 0x03f8, IRQ: 4
/dev/ttyS1, UART: unknown, Port: 0x02f8, IRQ: 3
/dev/ttyS2, UART: 16550A, Port: 0x03e8, IRQ: 4
/dev/ttyS3, UART: unknown, Port: 0x02e8, IRQ: 3

{dirk@wanchai}[/home/dirk]echo blahblah > /dev/ttyS0
/dev/ttyS0: No such device.

{dirk@wanchai}[/home/dirk]sudo echo blahblah > /dev/ttyS0
/dev/ttyS0: No such device.

{dirk@wanchai}[/home/dirk]dmesg | tail -3
[17204867.876000] ttyS0: LSR safety check engaged!
[17204885.488000] ttyS0: LSR safety check engaged!
[17204901.476000] ttyS0: LSR safety check engaged!