fresh install ---blooming DVD drive not recognized AGAIN

Basil Chupin blchupin at
Mon Jan 16 04:35:44 UTC 2012

On 16/01/12 15:09, Basil Chupin wrote:
> On 16/01/12 14:41, Ric Moore wrote:
>> On 01/15/2012 08:17 PM, Basil Chupin wrote:
>>> Yesterday, after several frustrating hours where I could not get my
>>> wife's computer to work properly (I had to move the system into a new
>>> box - don't ask :-) ), I realised that one should prepare a check list
>>> of what to do when tackling a damn computer's innards and tick them off
>>> as the work progresses :-( .
>> I always mean to do that, but I get into "Master of the Universe" 
>> mode, with the skin of my scalp pulsing and bulging from all the 
>> brains packed under there, and think I'll remember it all. <sighs> I 
>> know, someone just shoot me.
>>> I couldn't get the darn thing to work properly because......I had
>>> forgotten to check that the jumpers on the HDs and the CDROM and DVD
>>> burner were correctly set :-( .
>>> So, are your jumpers all set correctly?
>> But of course. <smirks> I have one harddrive and one CD/DVD r/w. Both 
>> are set to "master", as each is on it's own cable and both are IDE.
> OK, both on separate cables and both set to Master. Positive?
>>> means that rather than use the 80-wire cable you regressed to the old
>>> 40-wire cable - which is why you are getting the message that your UDMA
>>> is now only 33 "due to 40-wire cable". S
>> Secondly, you state above that you use a "newer fat one" IDE cable. This
>> Nah, I should have been clearer... I used a NEWER "fatter" IDE ribbon 
>> cable to the DVD drive. It's still the old IDE flat ribbon style 
>> though. It LOOKS nicer, and a little more heavy duty, so it ought to 
>> work better? Heh, the optimistic side of me shows.
> So this newer cable IS 80-wire cable, right?
> In which case the kernel is not recognising the full UDMA of the drive 
> because it is giving you the message that the UDMA is restricted to 33 
> because of the "40-wire cable". To get the full UDMA for your drive 
> you then need to apply the fiddle I gave in my previous response.

I shouldn't have skimmed over your reply and should have written above 
that the fix you ought to be using is  'libata.force=2:80c' because your 
DVD R/W is on the second channel. But if both the HD and the DVD are 
showing the wrong UDMA then use 'libata=1:80c,2:80c'  (which is what I 
have to use because I have HD and DVD R/W on channel #1 and HD and DVD 
R/W on channel #2 and without the fix dmesg shows that all are 
configured to UDMA33 because of the "40-wire cable" trick.)


It is easy to convince people of something, but hard to keep them convinced.
                              Niccolo Machiavelli

More information about the ubuntu-users mailing list