Dual boot with CentOS

[Robert Fitzpatrick]

I have installed CentOS 5.2 on a second hard drive and choosing no when
asking to setup grub on my /dev/hda, leaving my Ubuntu grub intact, now
how do I add CentOS to grub in Ubuntu? My existing grub menu.1st file
looks like this...

title Ubuntu 8.10, kernel 2.6.27-13-generic
root (hd0,3)
kernel /boot/vmlinuz-2.6.27-13-generic root=/dev/sda4 ro quiet splash
initrd /boot/initrd.img-2.6.27-13-generic

title Ubuntu 8.10, kernel 2.6.27-13-generic (recovery mode)
root (hd0,3)
kernel /boot/vmlinuz-2.6.27-13-generic root=/dev/sda4 ro  single
initrd /boot/initrd.img-2.6.27-13-generic

Also, my system looks like this....

robert at columbus:~$ fdisk -l

Disk /dev/sda: 160.0 GB, 160041885696 bytes
255 heads, 63 sectors/track, 19457 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Disk identifier: 0x0000f444

   Device Boot      Start         End      Blocks   Id  System
/dev/sda1   *           1         129     1036161   82  Linux swap / Solaris
/dev/sda2             130        3316    25599577+   5  Extended
/dev/sda3            6504       19457   104053005   83  Linux
/dev/sda4            3317        6503    25599577+  83  Linux
/dev/sda5             130        3316    25599546   83  Linux

Partition table entries are not in disk order

Disk /dev/sdb: 160.0 GB, 160041885696 bytes
255 heads, 63 sectors/track, 19457 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Disk identifier: 0x212d5ea7

   Device Boot      Start         End      Blocks   Id  System
/dev/sdb1   *           1        5099    40957686   83  Linux
/dev/sdb2            5100       19457   115330635   83  Linux

I tried the following added to the end of menu.1st, but get an error -
invalid or unsupported executable format...

title CentOS 5.2
root (hd1,0)
kernel /boot/vmlinuz-2.6.18-92.el5xen root=/dev/sdb1 ro quiet splash
initrd /boot/initrd-2.6.18-92.el5xen.img

I've tried several googled variations using 'makeactive' and
'chainloader +1', but nothing works yet.

-- 
Robert