This patch, against 2.4.20, updates 3c59x to vanilla Don Becker version 
that is available at ftp://www.scyld.com/pub/network/3c59x.c

It's too big post on a list, so I put it up at
ftp://ftp.kernel.org/pub/linux/kernel/people/jgarzik/patches/2.4.20/3c59x-vanilla-2.4.20.patch.gz

It's also available from BitKeeper at the 'bk pull' URL attached to this 
email.  But be warned you are pulling from 2.4.21-bk-current, plus 
3c59x.c changes, not vanilla 2.4.20 as the patch is diff'd against.