Hello! Thank you for your help! Here's what works for me (thanks to Seth Bardash, Nick Webb, and Alan Cudmore), although there's a caveat: 1. yum install kernel-devel 2. Obtain kernel-2.6.9-42.EL.src.rpm (which can be obtained from http://www.gtlib.gatech.edu/pub/centos/4/os/SRPMS Now, for the caveat: this kernel-2.6.9-42.EL.src.rpm, NOT kernel-2.6.9-42.ELsmp.src.rpm, which I still haven't found. This means that the four-cpu machine needs to be brought up as a single-cpu machine. 3. Install kernel SRPM: rpm -ivh kernel-2.6.9-42.EL.src.rpm 4. rpmbuild -bp --target $(uname -m) kernel.2.6.9-42.EL.src.rpm 5. (kernel source is now in /usr/src/redhat/BUILD/kernel-2.6.9/linux-2.6.9) cd /usr/src/redhat/BUILD/kernel-2.6.9/linux-2.6.9 Now, for the steps I used to install the arcnet driver, which is why I needed to do the above: 6. make menuconfig (enable arcnet modules) Device Drivers:Networking Support:Network Device Support:Arcnet Devices (press "M", get another menu, "M"-ize the selections there) 7. make 8. Insert the modules into the current kernel: cd /usr/src/redhat/BUILD/kernel-2.6.9/linux-2.6.9/drivers/net/arcnet insmod arcnet.ko insmod arc-rawmode.ko insmod com20020.ko insmod com20020-pci.ko node=3 device=arc0 timeout=3 backplane=0 clockp=0 clockm=0 insmod rfc1201.ko ifconfig arc0 up If anyone has some more hints about how to get ...ELsmp... instead of just EL, I'd appreciate it! Hmm, Nick Webb said something about enabling SMP support, so perhaps I'll take another look for it in menuconfig... Thank you, Charles Campbell