I'm pretty new to linux. I just installed Slackware 8.1, and every time i startx, i get the message "device /dev/dsp can't be opened (no such device)". but when i look in /dev, i see it there. can anyone please tell me what the problem is?

Check your access permissions.

Check your pci listing (/sbin/lspci) - does your system regognise the sound card?

could be arts starting up with KDE, in which case it may or may not be a problem. If you're using a kernel configured soundcard, then odds are sound still works fine, in which you can just tell kde not to start arts.

Does the sound work, say when you use xmms to output via the oss driver?
and as tomto pointed out, your access permission to /dev/dsp might be the problem.

i check access permissions and they are ok. i get the same problem as root.

i believe my audio controller is a Cirrus Logic/Crystal CS4205


here is what lspci returns:

00:00.0 Host bridge: Intel Corp. 82845 845 (Brookdale) Chipset Host Bridge (rev 04)
00:01.0 PCI bridge: Intel Corp. 82845 845 (Brookdale) Chipset AGP Bridge (rev 04)
00:1d.0 USB Controller: Intel Corp. 82801CA/CAM USB (Hub #1) (rev 02)
00:1d.2 USB Controller: Intel Corp. 82801CA/CAM USB (Hub #3) (rev 02)
00:1e.0 PCI bridge: Intel Corp. 82801BAM/CAM PCI Bridge (rev 42)
00:1f.0 ISA bridge: Intel Corp. 82801CAM ISA Bridge (LPC) (rev 02)
00:1f.1 IDE interface: Intel Corp. 82801CAM IDE U100 (rev 02)
00:1f.5 Multimedia audio controller: Intel Corp. 82801CA/CAM AC'97 Audio (rev 02)
00:1f.6 Modem: Intel Corp. 82801CA/CAM AC'97 Modem (rev 02)
01:00.0 VGA compatible controller: ATI Technologies Inc: Unknown device 4c66 (rev 01)
02:00.0 Ethernet controller: 3Com Corporation 3c905C-TX/TX-M [Tornado] (rev 78)
02:01.0 CardBus bridge: Texas Instruments PCI4451 PC card Cardbus Controller
02:01.1 CardBus bridge: Texas Instruments PCI4451 PC card Cardbus Controller
02:01.2 FireWire (IEEE 1394): Texas Instruments PCI4451 IEEE-1394 Controller

never mind. problem solved. all i needed was
modprobe soundcore
modprobe i810_audio

yeah, i know. stupidly simple problem. but hey, im new at this. hehe

Don't beat yourself up, man. Having problems and making mistakes are the ways you learn.