I have a Dell Optiplex GX1 (Pentium III 450) and the cdrom drive is not being detected during installation. I started by trying to install slackware 10, and tried the basic ide kernel and the ide raid kernel and when it gets to the point of accessing the install source from the disc, it says it cannot find a cdrom drive. The drive is the secondary master, with nothing slaved to it. There are two 4 GB hard drives on the primary channel (different models). I tried both the auto detect and manually chosing the hdc drive. When the kernel boots it says something like hdc: samsung atapi cdrom drive, but when the system boots i can't access it. I also tried using knoppix, and it will boot from the cd, but it searches for a cdrom drive and then says it can't find a knoppix filesystem, and drops out to a command prompt. Red Hat 9 finds the cd drive and loads from it but is very slow (like 1x read speed). Dos reads the drive fine and there isn't anything out of the ordinary about it as far as i know, i've been using it in windows for a while. Please help.

Is your CD drive set to 2nd Master or is it set to "cable select"?

The CD was set as cable select. I changed the jumper to master, but this didn't change anything.

Also, if I choose "failsafe" when booting knoppix, it works, but if I use the default kernel it doesn't. I'm not familiar with the linux kernel or modules, so any help in this area would be appreciated.

Problem fixed:

It finds the cd with the option "nodma".

Congrats on solving the problem and thanks for posting back with the solution; that will be helpful to future readers who may run into the same issue. -- J.W.