Very good points all around! I can't wait to do more tests! Thanks for now!

If a long IDE cable will work with a hard drive, it will work with your extender. IDE hard drives literally run the ISA bus down the ribbon cable. Electrically there is no difference between what you are doing and what a hard drive is doing.

But at a certain speed IDE requires 80 conductor cables. I guess that's not happening on an ISA IDE controller though?

tony359 wrote on 2024-05-25, 21:23:

Very good points all around! I can't wait to do more tests! Thanks for now!

If a long IDE cable will work with a hard drive, it will work with your extender. IDE hard drives literally run the ISA bus down the ribbon cable. Electrically there is no difference between what you are doing and what a hard drive is doing.

But at a certain speed IDE requires 80 conductor cables. I guess that's not happening on an ISA IDE controller though?

Correct. Here's the cycle times for UDMA modes:

Frequency is the reciprocal of cycle time. ISA bus is going to be about 120ns.

Also, here's the spec on the absolute max an ISA card can pull on each rail. If you want to incorporate fuses of some kind.

Thanks for the power table, that's going to be useful for sure! Fuses sound like a very good idea.

Gotcha about speeds. So ISA is limited to ATA33 - as we all know - and more than that it's going to be PCI based, which also needs better shielding. Very interesting. Cheers!

tony359 wrote on 2024-05-25, 21:06:

maxtherabbit wrote on 2024-05-25, 20:58:

This. I would not use the 80C IDE cables, I don't think ISA is fast enough that interspersing ground wires will be required.

Well I guess it wouldn't hurt?

It might hurt for the reasons mkarcher posted above

Well, obviously I will design the connectors so that the pins are in the right place. I'm not thinking of just plugging 80 conductor wires ribbons in the existing sockets - which are 50 ways anyways. It needs a re-design of course.

tony359 wrote on 2024-05-26, 17:41:

Well, obviously I will design the connectors so that the pins are in the right place. I'm not thinking of just plugging 80 conductor wires ribbons in the existing sockets - which are 50 ways anyways. It needs a re-design of course.

Yes of course as long as you mind the ground pin and presence detect pin concerns it would be perfectly fine

I’m looking at doing this… did you get anywhere with success??

yes and no.

The extender worked once I wired the POWER lines using proper cables. Then I decided NOT to improve on that design and I just made a simple 16bit 90 degrees adaptor.

https://www.pcbway.com/project/shareproject/1 … r_175d8c84.html

(the project is free to download. If you order through PCBWay I get 10% I think - just to be clear).

If you're interested in the original project, I could upload it on github - Honestly I think that if you used a decent ribbon cable, it would work. Mine was VERY flexible, indicating very small conductors.
Ideally you'd want to wire the power using a power connector, problem solved. But also soldering some wires works.