sr_mod module

[Victor Tsaran]

Hello, listers!
I finally got down to reading the CD-writing-howto file. I am using
Redhat7.0 and cannot find anywhere the module by the name sr_mod,
which the author is often refering to. I, however, can load one CDROM
as an IDE device and another as SCSI-emulated one under
/dev/scd0. What is the purpose of sr_mod module then and where should
I look for it in Redhat distribution?
Thanks,
Victor