When is a hard drive valid?

I have a strange situation (to me anyway).
I have three hard drives plus a dvd burner.
Normally they are connected as:
Primary Master = hard drive # 1. (Vista)
Primary Slave = hard drive # 2. (XP SP1)
Secondary Master = hard drive # 3. (XP SP1)
Secondary Slave = DVD burner.
Hard drive # 1 was created earlier by Acronis as a clone of another
smaller drive. This may not be important.
My BIOS fails to recognize hard drive # 2 at all.
When I manually rewire things, swapping the two Slaves, things work
just fine. That is, my BIOS recognizes all drives.

So my questions are:
Is the first hard drive somehow preventing the second hard drive from
being present on the same channel? If so how?
Why does the second hard drive work as Secondary Slave, but not as
Primary Slave? If the drive jumpers are the culprit, I sure would
like to know how.

Thanks
-GECKO

On Mon, 23 Jun 2008 23:46:55 GMT, gecko <alpha@olympus.net>
wrote:

>Primary Master = hard drive # 1. (Vista)
>Primary Slave = hard drive # 2. (XP SP1)
>Secondary Master = hard drive # 3. (XP SP1)
>Secondary Slave = DVD burner.

>My BIOS fails to recognize hard drive # 2 at all.
>When I manually rewire things, swapping the two Slaves, things work
>just fine. That is, my BIOS recognizes all drives.

>Is the first hard drive somehow preventing the second hard drive from
>being present on the same channel?

Some brands / types of harddisk are just very hard to mix.
Work around include puting them on separate channels as you found
out.

In some cases, switching to cable select solves the conflict.

And in all cases: if you are using 80-wire ATA cables, make sure
that you connect them correctly: blue to the motherboard, black
as master, gray as slave.

--
Kind regards,
Gerard Bok

On Wed, 25 Jun 2008 13:15:23 GMT, bok118@zonnet.nl (Gerard Bok) wrote:


>Some brands / types of harddisk are just very hard to mix.
>Work around include puting them on separate channels as you found
>out.
>
>In some cases, switching to cable select solves the conflict.
>
>And in all cases: if you are using 80-wire ATA cables, make sure
>that you connect them correctly: blue to the motherboard, black
>as master, gray as slave.

Thanks for reply.

I think you are right.

I did do something that made a difference. I changed IDE cables
(80-wire). At least for now, the problem went away. Sure was a new
problem for me.

-GECKO

gecko wrote:
> On Wed, 25 Jun 2008 13:15:23 GMT, bok118@zonnet.nl (Gerard Bok) wrote:
>
>
>> Some brands / types of harddisk are just very hard to mix.
>> Work around include puting them on separate channels as you found
>> out.
>>
>> In some cases, switching to cable select solves the conflict.
>>
>> And in all cases: if you are using 80-wire ATA cables, make sure
>> that you connect them correctly: blue to the motherboard, black
>> as master, gray as slave.
>
> Thanks for reply.
>
> I think you are right.
>
> I did do something that made a difference. I changed IDE cables
> (80-wire). At least for now, the problem went away. Sure was a new
> problem for me.
>
> -GECKO

80 wire cables have better signal integrity. The ATA/ATAPI standard
even has a provision for driver software to detect that an 80 wire
cable is in use - that also enables the higher transfer rates, because
they know an 80 wire cable does a better job.

See "Ultra DMA (80-Conductor) IDE/ATA Cables" here -

http://www.pcguide.com/ref/hdd/if/ide/conf.htm

Paul