[CentOS] Getting kernel source for 2.6.9-42.ELsmp

[Charles E Campbell Jr]

Hello!

I need to get an arcnet device driver up and running.  Normally it 
appears to be distributed with linux, but not installed.  So, I need to 
compile and install it, naturally.
So, where is the kernel souce for 2.6.9-42.ELsmp?  I can find kernel 
source for 2.6.9.
BTW, I obtained 2.6.9 and tried compiling it, but all I got was *.o 
files and

  insmod: error inserting 'arcnet.o`: -1 Invalid module format

Seems that the rest of the 
/lib/modules/2.6.9-42.ELsmp/kernel/drivers/net appear to be *.ko files.

Hope y'all can help!
Charles Campbell

P.S. sorry if this is a duplicate; my first copy went out over an hour 
ago and I didn't see it show up