From what I see, 6BXC rev1.7 also has the missing pin, at least from Robert B's photo.

You can just clear the hole that's missing on the 80pin cables - I usually do that so I don't have to swap cables when moving mainboards. (e.g MSI 694D Pro-AR and DTK PRM27i E0)

PcBytes wrote on 2024-02-23, 17:32:

You can just clear the hole that's missing on the 80pin cables - I usually do that so I don't have to swap cables when moving mainboards. (e.g MSI 694D Pro-AR and DTK PRM27i E0)

I've never done that - would you be limited to one device on that cable or no?

Since the pin is technically the only thing mechanically preventing insertion, no. You're basically using the cables as if they were standard 40pin IDE - the pincount remains the same, it's the conductor that differs.

PcBytes wrote on 2024-02-23, 17:32:

From what I see, 6BXC rev1.7 also has the missing pin, at least from Robert B's photo.

You can just clear the hole that's missing on the 80pin cables - I usually do that so I don't have to swap cables when moving mainboards. (e.g MSI 694D Pro-AR and DTK PRM27i E0)

No, it doesn't have, it's imperfection in photo.
Here's another one, from Tiget Technik
https://www.tiger-technik.de/Mainboards/Intel … m577::3934.html
download/file.php?mode=view&id=186287

Anyway, still not answer for my question 0 why motherboard manufacturers was doing it... Why to place PATA-66 connectors on UDMA33 board, and if it has any benefits, why all of the manufacturers wasn't doing it? Could cause only problems for people, with old 40 wire cables inside case.

You need to worry about it as much as plugging a USB 2.1 extension cable into a USB 1.1 port or a Cat 6 LAN cable into a 10baseT adapter... i.e. not at all.

W.x. wrote on 2024-02-23, 19:50:

No, it doesn't have, it's imperfection in photo.

And I found several 1.7s with missing pins, one of them off a eBay listing. I am fairly sure those aren't imperfections, rather a transition to the standard 80pin done during their apparition.

It's not even solely an ATA66 thing, some manufacturers did it back in the late 80s into 90s, it was always a pain the ass.

BitWrangler wrote on 2024-02-23, 20:26:

It's not even solely an ATA66 thing, some manufacturers did it back in the late 80s into 90s, it was always a pain the ass.

Even more so as even the old HDDs that first started using IDE (Miniscribe for example) don't use that pin either.

The pin being present is known to cause issues on some CF adapters.

However... what I tended to do (but which is very naughty and bad, and you probably shouldnt do it!), was to take a sewing needle or sewing pin, hold it in a pair of needlenose pliers, heat it up with a butane lighter, then press it into the space where a hole SHOULD BE, to MAKE a hole.

This allows the cable to go on just fine.

Usually, it's hollow inside, with just a small rind of plastic, so you dont have to push hard.

But not always.... some were very aggressive and solid plastic in there.

Some just have a white, or kinda hard to tell black, plug in there that you can just flick out with the point of a sharp craft knife. I also hate the ones that are solid right through, same with some VGA sockets. I have a tiny drill I sometimes use, sometimes use the hot needle method also.

It's ok, I have many 40wire and 80wire IDE cables, I just use 40pin cable... even on ATA-100 Hard-drive. UDMA33 on integrated IDE controller, would still limit it around 20-25MB/sec, so I think 80wire cable wouldn't make any difference. But I've heard, they have better signal transfer than over 40pin.

80 wire, not 80 pin 😀
Makes no difference on UDMA33 board. 80 wire cable gives you extra guard traces between every signal wire https://blog.lamsimenterprises.com/2013/04/12 … races-worth-it/ Required for error free UDMA66-133 transmission.

W.x. wrote on 2024-02-23, 21:56:

It's ok, I have many 40wire and 80wire IDE cables, I just use 40pin cable... even on ATA-100 Hard-drive. UDMA33 on integrated IDE controller, would still limit it around 20-25MB/sec, so I think 80wire cable wouldn't make any difference. But I've heard, they have better signal transfer than over 40pin.

There are also 80 wire cables with 40 holes and 40 wire cables with 39 holes.

As that pin is N/C or "Not Connected" it doesn't matter at all for functionality, or at least should not - as some CF cards behave weirdly if it is present. I have the luxury of too many cables, so to maximize compatibility I discard cables with connectors without that 40th hole. Makes life a lot easier.

Well, we all care about specifications.
Wait. Wasn't there a maximum cable length of 18 inches (45,7 cm) on PATA? That would be funny if both channels are on one electrical connection, haha.

And a NC pin has to be "not connected".
However, it is well known that several DOMs take usage of +5 V on that key pin.

Basically I use both 40 and 80 wire cables. And both connectors with 39 and 40 holes. If a connector with 39 pins doesn't fit on a motherboard you can either remove one pin on the connector of the motherboard or drill a hole into a connector on the cable. I prefer the latter and drill a hole with one of my smallest screwdrivers.

I use 80 conductor cables on retro IDE controllers/mobos that predate ata66 all the time. Just take a thumb tac, or a paper clip, heat the pin and push it in the blocker hole on the cable. To make the hole. Then be sure to put it on the correct way. It will function like a 40 conductor cable.