Quick questions about EIDE Laptop vs Desktop HDD data connectors & adapters

(Since this is a lot of questions, even tho they're probably easy for you guys, I'll make this post worth 250 pts. There are links to pics  for all this below.)
I'm trying to connect a Fujitsu model mhv2080ah laptop EIDE HDD to my regular desktop PC's PATA hard drive data connectors.  I didn't know laptop hdd's have different connectors. When I saw the difference I bought a '2.5" to 3.5" HDD adapter'.   But when I tried to plug it in I saw there was an even smaller PREVIOUS adapter stuck on the connector of the laptop HD, that let it connect to the laptop.  Let's call this PREVIOUS adapter the "mystery adapter", and my newer adapter a '2.5 to 3.5' adapter.

(1) Can you look at the picture (link below) of the "mystery adapter" and tell me what kind of connector the male end is called? And confirm that the female end is a '2.5" HD female connector'?

(2) Am I correct in assuming that most EIDE PATA hard drives for laptops are called '2.5" connectors' as opposed to the regular desktop HD connectors that are called 3.5"s?

(3) Does this '3.5" vs 2.5" HD' distinction apply for SATA drives as well?

(4) Most 80-pin eide / pata cables have one of the middle holes plugged.  But the "2.5 to 3.5" adapter I bought does not have the missing pin. So the 3.5" male end can't work with most EIDE / PATA cables. (It needs all holes free, unplugged).  Did I buy the wrong adapter?

(5) I eventually found an 80-pin EIDE PATA cable that had connectors at each end that had no plugged holes. I was able use it with the adapter + laptop HDD.  (including 2 pins for power, leading to the PATA power dongle).  See pic below, "3.5-to-2.5-hdd-pluggedin.jpg")  However, this setup didn't work. Any ideas why the desktop PC didn't detect the 2.5" drive? Do I need a special motherboard?

(6) I will assume that the picture called "naked 2.5-HDD-connector.jpg" shows a "2.5" male connector.  When I slap the 2.5 to 3.5 converter onto this, there are approx 4 pins unused. What are they for?


Links to pictures:
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I'll not adhere to your structure, but here goes:

The "mystery adapter" is brand/model specific and should of course be removed before the "2.5 to 3.5" adapter is put in place. The interface of the HD proper (some 30 pins in 2 rows) is standardised for 2.5" hard drives.

The key pin (often a missing pin corresponding to a blocked hole) is something used to help users attach the connectors the right way. If either is missing (i.e, the missing pin is there and/or the hole is not blocked, some models have a slotted sleeve for one connector that should match a small protrusion on the other connector. Missing both systems calls for the user to identify pin # 1 (normally identified on the mobo by a "1") and lead # 1 in the cable (the lead is usually red).

Putting either connector on backwards will cause the drive to fail detection, but shouldn't harm it.

On 2.5" HD's, one end of the pin row has pins for master/slave jumpers. These pins are not to be covered by the adpater connector. It may be possible to attach the adpater connector to cover these by mistake...


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dgrrrAuthor Commented:
Thanks, almost everything cleared up.

So it seems my "mystery connector" might be unique to Dell / Dell Dimension 6000? (the laptop type). (If anyone knows if these fall into general types/namess pls post)

Same goes if NE1 knows if these PATA 2.5" vs 3.5" HD types / sizes appliy also to SATA hard drives.

(I'll give a few points - most or all will go to RID)
The mystery connectors can look similar between brands/models of laptops, but I wouldn't bet they are interchangeable; some actually use the "naked" HD interface. Only drawback with that is that it requires more force to get them into or out of their place than the ones that have an edge connector (like in your pic).

I believe the physical size of HD's is described in the same manner with SATA and PATA drives. Indeed, I wouldn't be surprised if the mechanics are all the same and the difference is only in the circuit board of the HD.
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what model is your disk?
dgrrrAuthor Commented:
Fujitsu model mhv2080ah laptop EIDE HDD
There is a very good site here: www.pc-disk.de
That disk can't be found there, oddly enough... but the connector(s) on 2.5" disks are standardised, just as the ones on 3.5" disks are. SATA connectors are different, the big idea being to send data through a serial interface (few leads) rather than in parallel (many leads). Those, too, are subject to a standard. The intermediate connector found on some laptop disks is a proprietary component.
here it shows a normal ata - ide interface :

dgrrrAuthor Commented:
Great info, thanks you guys.
dgrrrAuthor Commented:
BTW, now I see why they put on that "mystery" adapter, between the male 2.5" drive connector and the laptop interior motherboard.

The 2.5" ide male pins are susceptible to bending. Mine got bent a little even when I was being careful - I had to carefully unbend them.

Add this to the fact that you install a laptop HD by jamming it into the slot -- and you could easily get bent pins.

Whereas the "mystery" connector's male end has no pins. It's more like the edge of a PCI card. No pins to get bent.
I agree fully. The edge connectors are much more robust and require less force to get mated.
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