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IDC cable pitch for floppy drive

Posted: 21 Dec 2025 14:35
by Pacman
What's the pitch/spacing of the 34-pin floppy disk drive IDC cable?
It seems to be 2.54mm, but with an ageing eyesight I can't be 100% sure.

I need to replace the cable in my STe due to recasing, and am thinking about ordering a new one from Ali Express, except most of the cables are for PCs (twisted wires), so I believe the best solution would be to just buy a suitable lengthed IDC cable, and attach a couple of 34 pin female IDC connectors at each end.
By the way, what is the maximum length I can have the cable without causing issues?

Re: IDC cable pitch for floppy drive

Posted: 21 Dec 2025 16:58
by rubber_jonnie
Pacman wrote: 21 Dec 2025 14:35 What's the pitch/spacing of the 34-pin floppy disk drive IDC cable?
It seems to be 2.54mm, but with an ageing eyesight I can't be 100% sure.

I need to replace the cable in my STe due to recasing, and am thinking about ordering a new one from Ali Express, except most of the cables are for PCs (twisted wires), so I believe the best solution would be to just buy a suitable lengthed IDC cable, and attach a couple of 34 pin female IDC connectors at each end.
By the way, what is the maximum length I can have the cable without causing issues?
Pretty sure the plug pitch is 2.54mm so a standard bit of header will fit into the plug. As for length I have a cable that's about 3 ft in length for one of my machines and it works fine with up to 2 drives.

Re: IDC cable pitch for floppy drive

Posted: 21 Dec 2025 17:40
by LarryL
The IDC header pitch is 2.54mm
But since the header has two rows, the pitch of the cable is 1.27mm

Re: IDC cable pitch for floppy drive

Posted: 21 Dec 2025 21:25
by Pacman
Thanks guys.
I'll just order a 1m cable (34 pins/1.27mm spacing) and a bunch of female headers (34 pin, double row, 2.54mm spacing) then, attach a header at each end, and if I find I need it shorter after having done the recasing I'll just snap on a third header at the desired length and cut the cable shorter after it (or leave it as it is if an unterminated cable like that won't cause any issues).