disabling ata devices

[JM]

i'm not exactly sure how to accomplish this... i'm having problems with 
my cd-rom, which isn't surprising since it's a slim-line without UDMA 
and probably isn't supported... but... it's eating up time when i'm 
booting the system.  i've erased the fstab lines for acd0 but it's still 
probing the hardware when i boot the machine.  how do i completely 
disable probing for this device at startup?  if possible i'd like to 
just remove the device node altogether.  every time i remove /dev/acd0 
it's just recreated each time i restart.  not sure how to permanently 
remove it without physically removing it from the system.  is there 
anyway to remove the node without removing the iso9660 entry from the 
kernel?