Jtdcftul

I have found inexpensive (~$15) 3.5in floppy to USB adapter cables but have been unable to find a similar adapter for 5.25 floppy drives. Does anybody make such a thing?

Are the pinouts of a 3.5 the same as 5.25 so that I could just make a cable end converter for the 3.54 adapter?

The data pin-outs are the same, assuming a reasonably “new” 5.25” drive, not an early ‘80s model.

It was a common upgrade to replace the second 5.25” drive on an older machine with a 3.5” one, so you could have a choice of format depending on your needs. They were interchangeable.

You might have an issue with the power though. I don’t remember seeing a 5.25” drive using the compact power connector pictured there. There might be, and I just don’t remember. There was another older connector type that was wider, with four tubular thick pins in a line. I’m learning that it is commonly referred to as “Molex” but that’s a company name. Power supplies typically provided both sets for choice of device. You will probably need an adapter cable for power. The electric characteristics are the same, it’s just a pin converter.

Be careful to get the right “direction”: you need a male 3.5” style to “molex 4 pin” female. The converter might be a bit hard to find because most people who needed a converter needed the opposite thing (plug a 3.5” drive on a 5.25”-only power supply). Cabling is not my area, so others might provide you with better information.

The connections on the 34-pin ribbon cables are identical, but the size of the connectors are different.

You can get ready made cables with both 5.25 and 3.5 connectors, for example http://www.cablesonline.com/36unflopdriv.html (and of course from Ebay also). These are likely to be more reliable than trying to wire a 5.25 connector onto a 3.5-sized cable by hand. These cables used IDC (insulation displacement) connectors which are crimped, not soldered, and they only work as designed with the correct size ribbon cable.

Rewiring the 4-pin power cable is a much more feasible proposition than rewiring the ribbon cable, if you can't find what you need ready-made. It should be possible to release the individual wires from the connector by pressing down the spring clip that locks the wire in place (visible through the slots in one side of the connector) with a thin screwdriver blade or something similar, while pulling on the wire. The wire itself is soldered onto the metal "pin and spring clip" part which goes into the plastic housing.

Perhaps FC5025 by Device Side Data would work? (it's read-only). Priced at $55.25.