I am trying to clean up a couple of single core computers and am unsure what is happening. I have the BIOS on each set to boot first from the CD ROM, then hdd. All hdds are jumpered to Master and are attached to the last (of 2) connectors with the CD Rom connected to the 'inner' connector and jumpered to slave.

I am using Ubunutu 8.04 Live CD which on one computer always boots fully, but when I run the partition editor, it can find only one (a 20 GB drive that came out of an older windows XP machine) of 5 (IDE) hdd's. The other 4 show the message "No Devices Detected"

The second computer will boot up the Live CD only on the same 20 GB hdd, and on all the others the live CD will not boot up fully.

AFAIK all the hdd's are OK, but this makes me wonder if the 4 are knackered?

Any ideas?

If you have 5 IDE HDs + 1 IDE CDROM then you have 6 IDE devices as opposed to the usual 4 on a MoBo. I would suspect that you have 1HD + 1CDROM on the MoBo's IDE channels and that your 4 HDs are on an IDE interface card. If Linux doesn't have a driver loaded for the IDE card, the partition software will not see the other drives. So - work out what driver that card needs and load it up from the installer via a shell before proceeding with the partitioning etc.

Also if all HD's are jumpered as master you would have to have each drive on it's own cable by itself..
You can not have two drives jumpered as master on a single cable..

Apologies. Initial post was confusing. I am only booting with one IDE hdd attached at a time. I.e., I'm trying the first, shutting down, trying the second, etc.

is hte IDE controller set to autodetect the Hard drive on Boot ? or are you going into BIOS each time after swapping the Hard drive and having it detect the new drive ?

If the Drives are Western Digital Hard rives you must set the Jumper to MASTER SINGLE, Rather than just MASTER if it is the only drive on the cable.

Apology for the quiet period, had to go out of town.

One of these two machines is a P3, the other is a later model single core AMD, and both have on-board IDE controllers. Does one set the autodetect option in BIOS? (The P3 is off the bench right now, so I can't boot it to nose around.)

Let me update on the AMD computer. I booted from a previously installed Ubunutu 8.04 hdd and in the shell ran

sudo fdisk -l

on each drive, one at a time.

Two of the four (one a 40GB WD and the other a Maxtor 120GB) did not respond and the other two both showed up in the shell.

Would you conclude from the above that the two non-responders are toes up?

most likely they are dead...

Can you feel the drive spin up when power is applied to it ?

no and they don't get warm. To the graveyard. Thanks.