Using those male-male pins won't work, because you end up switching the odd and even pins. (E.g. DOM pin 1 ends up on pin 2 on the cable, pin1 cable to pin2 DOM...).

For 80-wire detection you need to ground pin 34.

andrea wrote on 2020-11-29, 12:48:

Using those male-male pins won't work, because you end up switching the odd and even pins. (E.g. DOM pin 1 ends up on pin 2 on the cable, pin1 cable to pin2 DOM...).
For 80-wire detection you need to ground pin 34.

Thanks. That explanation was great.

I guess the only down side with that mod would be that the device won't work in a master/slave configuration any more, but that's probably not such a big deal when these devices sit directly on the adapter header.

Here's my UDMA mod for my CF adapter-- Soldiering isn't as nice as yours, but it was adequate I guess.

I tested a Lexar Pro CF that supports UDMA 7 with a VT8235 onboard controller (AK39n) and a Matrox PCI ATA133 card.
The CF now negotiates UDMA5 instead of UDMA2, which is a boost. Thanks again for your help.
Would have been nice to see UDMA6, because the CF and the board should support that, but SPEEDSYS doesn't report that as an option,

I also moded a LeiDisk industrial DOM -- It now negotiates UDMA4, which is the best it can do.

This guy is the next target. Has the exact same layout as the Leidisk, and they have the same controller chip as the hyper disk. Postest this picture to show what the flip side of the DOM looks like.

p.s. those DOMs have a similar controller to the 32MB Transcend-PSD330.

The Doms had SM223TF-AC
While the Transcend-PSD330 had SM2236G-AC

andrea wrote on 2020-11-29, 12:48:

Using those male-male pins won't work, because you end up switching the odd and even pins. (E.g. DOM pin 1 ends up on pin 2 on t […]
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Using those male-male pins won't work, because you end up switching the odd and even pins. (E.g. DOM pin 1 ends up on pin 2 on the cable, pin1 cable to pin2 DOM...).

For 80-wire detection you need to ground pin 34.

Thanks for the guide.
I used here -
Re: CF-Card DMA issue with my AMD K6-2 500 MHz SS7 Setup

This is my mod -

Question guys, what happens when you connect pin 34 to a ground pin and then attempt to use the CF adapter/DOM on an older controller? Let's say one that maxes out at UDMA2/ATA-33 or is even PIO-only, will it still be functional like before or is it affected in any way? (other than not being able to configure master/slave of course)

konc wrote on 2024-04-24, 18:32:

Question guys, what happens when you connect pin 34 to a ground pin and then attempt to use the CF adapter/DOM on an older controller? Let's say one that maxes out at UDMA2/ATA-33 or is even PIO-only, will it still be functional like before or is it affected in any way? (other than not being able to configure master/slave of course)

It is like using an 80 conductor cable on an old system. It works fine almost all the time. Maybe some of the really early IDE controllers might not like it.

douglar wrote on 2024-04-25, 02:10:

konc wrote on 2024-04-24, 18:32:

Question guys, what happens when you connect pin 34 to a ground pin and then attempt to use the CF adapter/DOM on an older controller? Let's say one that maxes out at UDMA2/ATA-33 or is even PIO-only, will it still be functional like before or is it affected in any way? (other than not being able to configure master/slave of course)

It is like using an 80 conductor cable on an old system. It works fine almost all the time. Maybe some of the really early IDE controllers might not like it.

Perfect thank you, that's what I expected. I was wondering why it's not like that from the beginning, especially for products like DOMs that are meant to be connected directly on the controller pins without a cable and don't even have a master/slave switch, and thought to ask in case there is an unknown (to me) side effect.