It was a long search but I finally managed to get a “standard” 8” floppy drive! I found it on Leboncoin for a reasonable price (75 EUR). It came in what seemed to be its original foam packaging:

It is a single side drive since it has but a single head:

The controller board has a 50 pin edge connector:

This will require a converter board to connect it using the more usual 34pin cable. This board can be ordered from Tindy, here. More information on 8” floppy drives can be seen on several CuriousMarc video’s.

.plan is to use this floppy with GreaseWeazle to create new formatted RX02 floppies for the DEC machines.

The device came with original documentation, 6 pages which I scanned to PDF: . For higher quality scans please contact me.

Testing the drive

Connectors…

The drive has some special form MOLEX connectors. I could not find these, so I decided to 3D print them:

This should make it easier to power the thing..

Powering up the logic

I tested the drive by putting it on my lab PSU. After switching the power on the 24V rail dropped to 3V and took 2A, so I switched off immediately. There was a burning smell in the air although nothing seemed hot and I did not see the Magic Smoke.

I measured the resistance of the 24V rail to GND which was 0.2ohm, really too low. Then I noticed the plethora of tantalums… I switched on the PSU again and quickly took a picture with the thermal camera:

The hot spots corresponded to some of the tantalums. I decided to replace them all:

There was one 33uF 35V that I did not have, I replaced that with a low ESR electrolytic one. After that the 24V rail behaved.