I think the pitch may be 1.27mm core center to core center

kaputnik wrote on 2024-01-27, 07:15:

Trying to source materials to press my own 40 pin 80 wire "UDMA IDE cables". Having a hard time finding anything but regular 40 pin IDC connectors, without the common ground connection for every other wire. Does anyone here happen to know the correct name/designation of the connectors used for 40 pin 80 wire IDE cables?

I'm sorry. I used to think that I recently researched into obtaining those connectors and found some, but my mind failed on me. The (discarded) idea was to use pre-made 80-conductor IDE cables for a different purpose, because of their cheap common availability (at that time). I tried to find individual IDC press-fit connectors for UDMA / PATA (should be helpful keywords) right now, but didn't get any usable results within a couple of minutes. Carefully prying them off old IDE cables might be the easiest choice if it's not about mass production.

kaputnik wrote on 2024-01-27, 07:15:

Also wondering what the wire pitch of those 80 wire ribbon cables is?

As the IDE connector is two rows of 2.54mm (0.1") pitch, the wire pitch of a standard (40-conductor) IDE cable is half of it (1.27mm, 0.05"). The 80-conductor cables have to have an extra ground wire, so the pitch is halved again to 0.635mm / 0.025". The usual cross section of the conductors in 80-conductor IDE cables is "AWG 30", which can also be a helpful search term when looking for this cable type. Cables like this can be found.

kaputnik wrote on 2024-01-27, 07:15:

Trying to source materials to press my own 40 pin 80 wire "UDMA IDE cables". Having a hard time finding anything but regular 40 pin IDC connectors, without the common ground connection for every other wire. Does anyone here happen to know the correct name/designation of the connectors used for 40 pin 80 wire IDE cables?

Also wondering what the wire pitch of those 80 wire ribbon cables is?

US-based though - https://www.cablesonline.us/40-80-ata-ide-fem … ck-blue-gray-1/

PC Hoarder Patrol wrote on 2024-01-27, 10:35:

US-based though - https://www.cablesonline.us/40-80-ata-ide-fem … ck-blue-gray-1/

That's definitely the correct items.

kaputnik wrote on 2024-01-27, 07:15:

Does anyone here happen to know the correct name/designation of the connectors used for 40 pin 80 wire IDE cables?

Please remeber that the color is not just for show: Each color of these connectors has a slightly different internal wiring to make Cable Select and 80-conductor cable recognition work. If you want to build your own cable, you need three differently colored connectors in the correct order (Master and Host connectors at the ends, optionally Slave connector in the middle).

Sphere478 wrote on 2024-01-27, 07:28:

I think the pitch may be 1.27mm core center to core center

mkarcher wrote on 2024-01-27, 10:16:

I'm sorry. I used to think that I recently researched into obtaining those connectors and found some, but my mind failed on me. The (discarded) idea was to use pre-made 80-conductor IDE cables for a different purpose, because of their cheap common availability (at that time). I tried to find individual IDC press-fit connectors for UDMA / PATA (should be helpful keywords) right now, but didn't get any usable results within a couple of minutes. Carefully prying them off old IDE cables might be the easiest choice if it's not about mass production.

As the IDE connector is two rows of 2.54mm (0.1") pitch, the wire pitch of a standard (40-conductor) IDE cable is half of it (1.27mm, 0.05"). The 80-conductor cables have to have an extra ground wire, so the pitch is halved again to 0.635mm / 0.025". The usual cross section of the conductors in 80-conductor IDE cables is "AWG 30", which can also be a helpful search term when looking for this cable type. Cables like this can be found.

Yeah, that's what I use to do when making custom ribbon cables. However, even though IDC connectors usually are specced for 20-30 cycles, a reused connector never is the same as a brand new one. Also, used ribbon cables with single strand conductors tend to look like crap, with permanent kinks, etc. Would be really nice to find somewhere to source new parts.

Not gonna mass produce, I'm just somewhat of a stickler when it comes to cable arrangement in my computers. Can't stand the standard mess with too long crappy looking cables 😀

Sounds plausible, at least the pitch should be something very close to 0.635mm. It would also be surprising if they didn't use some standard ribbon cable and developed something specifically for IDE cables instead. Admissible wire gauges are usually specced in the datasheet for IDC connectors.

PC Hoarder Patrol wrote on 2024-01-27, 10:35:

US-based though - https://www.cablesonline.us/40-80-ata-ide-fem … ck-blue-gray-1/

Regrettably, shipping rates from overseas to here usually are quite exorbitant. It helps me with search arguments though 😀

mkarcher wrote on 2024-01-27, 12:57:

Please remeber that the color is not just for show: Each color of these connectors has a slightly different internal wiring to make Cable Select and 80-conductor cable recognition work. If you want to build your own cable, you need three differently colored connectors in the correct order (Master and Host connectors at the ends, optionally Slave connector in the middle).

Yep, I'm aware. Screwed up with that first time I tried to adapt an 80 wire cable for use in an original Xbox. Tried to just cut the keys and drill out the plugged holes to be able to connect the cable the other way around, with the middle connector closer to the mobo. Didn't work, soon found out why 😀 When making your own cables, it's very easy to just pull/move the corresponding contacts from the connectors before pressing them onto the cable.

---

Thanks for the input guys!

mkarcher wrote on 2024-01-27, 12:57:

That's definitely the correct items. […]
Show full quote

PC Hoarder Patrol wrote on 2024-01-27, 10:35:

US-based though - https://www.cablesonline.us/40-80-ata-ide-fem … ck-blue-gray-1/

That's definitely the correct items.

kaputnik wrote on 2024-01-27, 07:15:

Does anyone here happen to know the correct name/designation of the connectors used for 40 pin 80 wire IDE cables?

Please remeber that the color is not just for show: Each color of these connectors has a slightly different internal wiring to make Cable Select and 80-conductor cable recognition work. If you want to build your own cable, you need three differently colored connectors in the correct order (Master and Host connectors at the ends, optionally Slave connector in the middle).

Thanks ! I always wondered why they were colored exactly a certain way on all my 80pin. Color is Host, grey slave mid, black master end. Thought it was just for visual ID.....

mkarcher wrote on 2024-01-27, 10:16:

I'm sorry. I used to think that I recently researched into obtaining those connectors and found some, but my mind failed on me. […]
Show full quote

kaputnik wrote on 2024-01-27, 07:15:

Trying to source materials to press my own 40 pin 80 wire "UDMA IDE cables". Having a hard time finding anything but regular 40 pin IDC connectors, without the common ground connection for every other wire. Does anyone here happen to know the correct name/designation of the connectors used for 40 pin 80 wire IDE cables?

I'm sorry. I used to think that I recently researched into obtaining those connectors and found some, but my mind failed on me. The (discarded) idea was to use pre-made 80-conductor IDE cables for a different purpose, because of their cheap common availability (at that time). I tried to find individual IDC press-fit connectors for UDMA / PATA (should be helpful keywords) right now, but didn't get any usable results within a couple of minutes. Carefully prying them off old IDE cables might be the easiest choice if it's not about mass production.

kaputnik wrote on 2024-01-27, 07:15:

Also wondering what the wire pitch of those 80 wire ribbon cables is?

As the IDE connector is two rows of 2.54mm (0.1") pitch, the wire pitch of a standard (40-conductor) IDE cable is half of it (1.27mm, 0.05"). The 80-conductor cables have to have an extra ground wire, so the pitch is halved again to 0.635mm / 0.025". The usual cross section of the conductors in 80-conductor IDE cables is "AWG 30", which can also be a helpful search term when looking for this cable type. Cables like this can be found.

Ah yes. It was late and I only halved once. What you say makes sense.

Keep in mind the 80 pin PATA cable is solid conductor, hence the stiff, bendy.

Cheers,

pentiumspeed wrote on 2024-01-27, 18:03:

Keep in mind the 80 pin PATA cable is solid conductor, hence the stiff, bendy.

Cheers,

I have a few multi strand examples in my collection. They are nice and bendy

The question I’ve always had is electrically what is the signal/ noise at ATA133 on an 80 conductor VRS 40 conductor.

The general engineering consensus is that guard traces and grounds do absolutely nothing to improve signal quality so why does the inline 80 conductor cable do anything?

rmay635703 wrote on 2024-01-27, 18:19:

The question I’ve always had is electrically what is the signal/ noise at ATA133 on an 80 conductor VRS 40 conductor.

The general engineering consensus is that guard traces and grounds do absolutely nothing to improve signal quality so why does the inline 80 conductor cable do anything?

The primary idea of the 80 conductor cable is to reduce cross-talk between the signal lines. Early versions of some Linux UDMA drivers didn't care about the 80-conductor detection. In that time, I had a UDMA66-capable controller and an UDMA66-capable drive, but only a 40-conductor cable on that channel, which I didn't care about, because the drive was considerably slower than 33MB/s anyway. Every time that system booted, Linux enabled UDMA66 (UDMA mode 4), but still during the boot process, the sheer amount of CRC errors caused Linux to drop down to UDMA mode 3. So this is anecdotal evidence that UDMA66 in fact does not work reliably on 40-conductor cables.

Sphere478 wrote on 2024-01-27, 18:11:

pentiumspeed wrote on 2024-01-27, 18:03:

Keep in mind the 80 pin PATA cable is solid conductor, hence the stiff, bendy.

Cheers,

I have a few multi strand examples in my collection. They are nice and bendy

Yep, seen both variants too. The single strand ones are considerably more common though.

rmay635703 wrote on 2024-01-27, 18:19:

The question I’ve always had is electrically what is the signal/ noise at ATA133 on an 80 conductor VRS 40 conductor.

The general engineering consensus is that guard traces and grounds do absolutely nothing to improve signal quality so why does the inline 80 conductor cable do anything?

A wild guess is that it primarily has to do with high frequencies, electric fields and parasitic capacitance. Haven't researched the matter though.

Also beware. Crimp this type of cable by hand is a pain in the ass.

majinga wrote on 2024-01-27, 21:34:

Also beware. Crimp this type of cable by hand is a pain in the ass.

It's not that bad if you're careful. Done it numerous times with just a watchmaker's vise, no special tools at all 😀

A vise seem a better option than the supposed hand tool for the job.

Once I tried to crimp a 50P ribbon cable with this tool, and it was a nightmare.

One can always use a door to crimp those end connectors on. connectors in the middle can be a little bit more troublesome using a door.