Making Home-Made IDE and Floppy Cables
After having an electrical tape rounding job for a while, I decided it was time to have something nice looking if I was going to window my case. I don’t really care for any of the pre-made cable solutions available so I figured why not make my own. Turns out they’re super easy, look great, and can be totally customized to fit your case!
First off you need to find your cable… There’s 2 kinds (probably more, that’s all I bothered looking at) you got your gray ribbon and your rainbow ribbon. Depending on the purpose you need different conductor amounts, 34 for floppy, 40 for up to ATA33, and 80 for ATA66+. There are also different spacing, .050″ for Floppy and ATA33, and .025″ for ATA66+. Of course you have different widths for different flavors of SCSI, etc, pick what ya need…
I have yet to find a decent supplier for 80-conductor .025″ center ribbon. If anyone knows of any, let me know.
| Jameco # | Description |
| 643655 | 34-conductor flat rainbow |
| 644033 | 34-conductor flat gray |
| 643697 | 40-conductor flat rainbow |
| 644113 | 40-conductor flat gray |
Next you need your IDC’s (insulation displacement connectors)… Pretty cut and dry, you need either 34, 40, or 80 contact ones to match the cable.
And again I’m still looking for the 80 contact ones. I’ve heard places like Fry’s have them, but we don’t have Fry’s out here, nor is that too useful since I usually mail order, so if someone finds them somewhere online, please let me know!
| Jameco # | Description |
| 32768 | IDC plug for 40-conductor |
| 32644 | IDC plug for 34-conductor |
And finally you need some type of crimper… You *can* use a normal table vise for this, maybe even vise grips and maybe maybe maybe maybe pliers but I wouldn’t recommend it since you’ll get uneven pressure. The best thing to do is to use IDC crimpers.
| Jameco # | Description |
| 73252 | Insulation Displacement Crimper |
Here are some pictures of the stuff I got…
 Most of the stuff I used |
 IDC Connector (40-contact) |
 IDC Crimpers |
For an IDE cable, we need not modify the cable to get it to work, but for a floppy cable we need to do a small tweak. If you want to have a 1 floppy drive cable, then you must put a twist in somewhere between the two connectors. The twist consists of wires 10-16 being swapped: 10 -> 16, 11 -> 15, 12 -> 14. These images will provide more detail:
 Single floppy drive cable |
 Dual floppy drive cable |
 Single floppy drive cable |
 Dual floppy drive cable |
Bare ribbon cable
As far as the maximum length for an IDE cable goes, it would seem 18″ is the max IDE/ATA spec. although I’ve seen 36″ and higher work so it’s trial and error. Also it really doesn’t matter how close your two drive connectors are to each other, so just put them where you want them to be for your particular need.
I basically measured up the distances between my IDE connectors on my mobo and added a little for slack and to account for a bit of shortening due to rounding the cables later on. Here’s what I got for one of my IDE chains. It’s about 10″ or so (the perspective is skewed a bit).
Now we clamp on the IDC connectors, these little guys have 80 little teeth (2 for each wire) that penetrate the insulation (displace it as it were) and make contact with the wire inside, pretty slick if you ask me, just line them up and crunch ’em down.
Here are some pics of the cables as they were added into my case. You can even see the remnants of the electrical tape rounded cable that were being replaced.
Partially complete cable
 Floppy done |
 Floppy (close) |
 Floppy + 1 IDE (Zip) |
 Done, 1 Floppy, 3 IDE |