Does Anyone know the max length of a single device ata cable. IIRC the Ata spec sites it as 5' but I hear that over 3 feet emi and resistance start making reliability go down. The longest single device cables I've been able to find are only 18" but I've seen dual device cables up to 36" I dont want to hafta buy a dual device cable just because I need a cable that long and that exposed connecter would look bad. So does any one know where to buy the longest (doesn't matter if its braided or sleeved) single device cable
36" is the longest I've seen, although I've heard of 48" ribbon cables. But I've never come across a single-drive cable at those lengths. Not sure on that 5' measurement---that may be for Serial ATA, but probably not ATA.
Here's your problem. The LONGEST recommended cable length between devices for Parallel ATA (PATA) is 18". Meaning, the length between controller and drive, drive and drive, can be at most 18". This is why you have a MASTER/SLAVE setup for PATA drives. The MASTER drive acts as a signal repeater for the SLAVE drive, to the controller, allowing for a 2x18" maximum cable length for two devices. If you stick a device on the longest portion of a DUAL drive cable, you are actually going OUTSIDE of the PATA specifications. Now, these are RECOMMENDED lengths. You can go higher, however, the device signal degrades pretty rapidly, so therefore, you may or may not have problems using 18+ inches per device. If all you are worried about is how the cable looks, you can ALWAYS find vendors that will do a CUSTOM cable for your, or possible build your OWN rounded cable, by seperating the wires and wrapping the wires in heat-shrink. Here is one place that I Googled which has single drive 36" PATA rounded cables... http://www.pixelusa.com/catalog/detail.asp?id=CB-IDE-01036A However, I have *never* purchased from this vendor. So I can not say if they are any good. Another option would be to get a cheap SATA card, and a SATA->PATA converter board (all in all, about $50US) to convert the drive to SATA. This works for HD's, if it is a CD-Rom drive (something that uses ATAPI, and not straight AT standard) you will have problems, as most SATA cards don't fully support the ATAPI standard over SATA. In that case, you might need to find a special controller card which will allow for it, or move the CD-Roms to the shorter cables, and move the HDs to the SATA setup. This would allow you to use the thin SATA cables, and give you 10' of distance. However, it's much more expensive. Hope this helps!
Yah that helps somewhat, unfortunately I dont have room for a sata controller card (look at the project log in the sig) and my onboard sata slots are already taken by My Raid array. The only signal being carried is a dvd/cdrw drive. I could just wing it and try maybe a 24" dual device cable. The reason I didn't care about the braided/unbraided, is because the whole cable will be resleeved in a Thick Cable from the original radio. Anyways I Think I'm gonna hafta either wing it. Dont they make pata->USb Like you see in external hard drive enclosures. The max length for a usb cable is long enough, do you think that would work?
Yeah.. that could work too. Never thought of that. You can find USB to PATA converters for about the same price ($50), and they should be able to handle the ATAPI devices just fine. You would need to go USB 2.0 if you want any type of speed out of it however, I wouldn't suggest going with a USB 1.1 device. You can find such devices at places like NewEgg http://www.newegg.com
hey just something I've never really asked, just presumed... I've been fiddling with hard disks since my Amstrad 2086 and I've always put the primary drive at the end of the cable with the secondary in the middle. Is this incorrect with the suggestion of using one as a repeater? Weird, just never thought of it before...
Actually, the pata cables you are referring are more commonly know as udma cables and are in fact limited to 18". However is you are only running optical drives on pata then just use the standard 40 pin ide cable which can be had in lengths of greater than 36", although not reccomended. you can also have a ide cable made with just 1 channel. seeing as how you will not find a udma cable longer that 18" it doesn't matter which port on the cable you use.
No not really, what I referring to was really bad language use on my part. I should have replaced the word, 'repeater' with 'terminator'. Quite frankly, I was thinking about IDE bus repeaters which you can purchase to 'massage' the data traffic and give you longer cable lengths at the time I was writing the reply (much like SCSI signal repeaters work), and I accidently used the term REPEATER instead of what I MEANT to say, which was TERMINATOR. MASTER/SLAVE jumpers on ATA drives have multiple uses: A. Since there can be 1 or 2 devices on the bus, the controller needs a way of identifying, and specifying which data needs to go to which device. This is done via the MASTER/SLAVE jumper (very much like the ID jumpers on SCSI devices). This was the first (original) designation for what master/slave does. Each IDE drive has it's own controller. So, to prevent each controller from listening to each other's traffic, you need a manner of identifying who the bus traffic should be going to, and hence the master/slave id. B. As part of extended signalling standards for the ATA (Ultra-Ata, ATAPI, etc.) specifications, most of the time, when enabling 'MASTER' on a drive, you also turn on bus termination (which assists in the signalling of data between devices). Some newer drives allow you to control this seperately via another jumper on the drive, however, the common mantra is that termination is turned on with the id selector in 'MASTER' position. Having the MASTER device in the middle of the bus won't necessarily hurt anything.... you'll just lose the advantages of the bus-termination on the 18" of cable between the MASTER drive and the SLAVE drive. So, any support the MASTER drive might be giving to the data signalling is lost. As a result, the 'ideal' is to have the MASTER on the end of the bus, and the SLAVE in the middle. However, as I stated before, some drives allow you to control this seperately, via another jumper, and therefore, this becomes moot in that case, as you can just control termination that way instead. I hope that clears things up a bit...sorry for the confusion.
Ah, cheers kt. That makes sense. It's bizzare that little things like drive order people "just know". Good in depth knowledge mind, next time I add a hard disk for someone I can give them plenty of banter!
