IDE Ribbon Cables?

[tinkertech]

I have two kinds of IDE Ribbon cables and I need some clarification if some one would please. Some of my 40-lead cables came with one of the connectors pluged. Others do not. Some old HD's have all 40 pins some others have 39 pins. Can some one lead me to where I can read on the subject? Thanks.

For every problem there is a solution, for every solution there is a tech behind it.

 

[cdogg]

Modern hard drives use only 39 pins, so that the direction of the cable is understood. The missing pin helps to signify the side that pin 1 is on, so that the cable is attached properly. On most, if not all current drives, pin 1 is always on the inside edge next to the power connector. The red stripe on the IDE cable is also another indicator of pin 1, so that you can visually see it's connected properly.

As far as one of the IDE connectors being "plugged", I'm assuming you mean it's capped in some way. Well, that is not necessary but helpful as far as keeping the connector free of dust.


~cdogg
[tab]"All paid jobs absorb and degrade the mind"
[tab][tab]- Aristotle
[navy]For general rules and guidelines to get better answers, click here:[/navy] faq219-2884

 

[edfair]

If you are lucky, the cable you have fits the drive you have. The missing pin/hole is an additional polarity enforcer for those IDH connectors that are not keyed.

Ed Fair
Give the wrong symptoms, get the wrong solutions.

 

[tinkertech]

Thanks for the replies. So you mean to tell me that the missing pin on the HDD or the IDE header on the MB is only for orientation? It has nothing to do with ATA 33 or 66 or 100?

For every problem there is a solution, for every solution there is a tech behind it.

 

[edfair]

It has been a while since I looked at the pinout, but if I recall correctly, that was all it was.

Ed Fair
Give the wrong symptoms, get the wrong solutions.

 

[cdogg]

I would also suspect that the HDD that has 40 pins was pre-ATA (probably at least 8-9 years old). Many modern IDE cables have a filled in hole where the missing pin is suppose to meet. Obviously, these cables cannot be used with the older drives that have all 40 pins present.

What is it that you're trying to accomplish here?


~cdogg
[tab]"All paid jobs absorb and degrade the mind"
[tab][tab]- Aristotle
[navy]For general rules and guidelines to get better answers, click here:[/navy] faq219-2884

 

[paparazi]

Most CDroms and some older HDD's are ATA33 or slower, they require the course wired 40pin plug/40core ribbon cable.
A few CDrom drives and Hard drives ATA66 or faster (ATA100/ATA133) use the fine 40pin plug/80core ribbon cable, recognised by it's much finer wire ribbon cable.
Martin

Replying helps further our knowledge, without comment leaves us wondering.

 

[tinkertech]

Like my name says, I was tinkering with this old system and when I went to connect the HD to the cable I noticed the plugged hole in the 40-wire cable. I thought it was some big deal. Not just orientation like I think I have been told here.

For every problem there is a solution, for every solution there is a tech behind it.

 

[cdogg]

tinkertech,
The point is that even on old hard drives, one pin never really mattered. This is the same pin that you see blocked out on modern IDE cables. As drives matured, so did the concept of making it easier on novice installers to make sure the IDE cable was inserted correctly. Thus came the "plugged hole" and "missing pin" on newer drives & cables. There's nothing fascinating or really mysterious about it - which I suspect you were hoping for.

This is about the only link I bothered to find that confirms the point that only 39 pins were ever in use:

www.mikeshardware.com/howtos/howto_c...

If you come across an in-depth explanation as to why, please post the link back here...

 

[edfair]

I took a quick look on the web and didn't find any other description than "key".

Ed Fair
Give the wrong symptoms, get the wrong solutions.

 

[cdogg]

Aha, found it!! I should have known better to go to PCGuide.com first and look for the explanation.

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

You will find, especially if you read the entire article, that the mysterious Pin 20 served no purpose beyond helping to key the proper orientation of the cable.


~cdogg
[tab]"All paid jobs absorb and degrade the mind"
[tab][tab]- Aristotle
[navy]For general rules and guidelines to get better answers, click here:[/navy] faq219-2884

 

[edfair]

But no more than 10% of the clone M/Bs or IDE cards came with plugged connectors. It must have been significantly cheaper to use the full 40 version.
Then the drive manufacturers started using the plastic shell and that resolved the errors.

Ed Fair
Give the wrong symptoms, get the wrong solutions.

 

[tinkertech]

Thank you all for the overwelming response to my simple question; I hope that many others, like myself, were enlighted by this information.

For every problem there is a solution, for every solution there is a tech behind it.