6.0 upgrade on 5.1 can't find cdrom

[Mark <salsa@pop3.spacestar.net>]

Upgrading 5.1 to 6.0.  On 5.1 install, used at boot prompt with floppy:
linux hdD=cdrom    - which worked fine.  With 6.0 boot floppy and :  linux
hdD=cdrom the cdrom can't be found with autoprobe.  Have even tried letters
a,b,c and d and A,B and C in the  linux hdX=cdrom line.  Why? and how to fix?

Upgrading on a Pachard Bell P60.

thanks, mark