E-MU Emulator II HxC Floppy Emulator

Ever since I got my EII I’ve been planning to add an HxC Floppy Emulator. These are some of the reasons:

  • One of the floppy drives doesn’t work and replacement drives are expensive
  • an SD card can hold a lot of floppy images
  • I don’t have a computer with a 5.25″ drive, so I have no way of transferring all the EII images I’ve got (could be solved if I get my Mac SE 30 and the serial thing working)

As the EII uses 5.25″ floppy drives, the connectors aren’t the same as for 3.5” drives. To solve this you basically have three alternatives:

  1. Create a new custom cable
  2. Create some kind of extension/adapter cable
  3. Modify the original cable

There’s a comprehensive manual from E M X P describing everything that you need to know about the HxC installation, including diagrams of the cables, whichever one you choose. Since I don’t like messing with the original one I chose to create one from scratch. I skipped the extension/adapter route since it would require a female 5.25″ connector, and I could as well create a whole new cable since I was messing with cables anyway. It’s also worth noticing that the cable is very long, almost a meter, which makes it nearly impossible to find a standard floppy cable and just add an extra 5.25″ male connector. In the picture below, taken from the manual, alternative 1 is the route I took. Alternative 2 shows the extension/adapter cable route.

Drawing of the 1) custom floppy cable that I make 2) The extension cable alternative. Screenshot from the E M X P manual (a must for everyone doing this conversion)
Drawing of the 1) custom floppy cable that I make 2) The extension cable alternative. Screenshot from the E M X P manual (a must for everyone doing this conversion)


  • About 1 m of 40-pin ribbon cable
  • Two standard 3.5″ floppy female connectors
  • One 5.25″ floppy female connector “34-way card edge connector IDC”
  • Lotharek REV F HxC drive (REV F is the 3.5″ floppy version). Buy it directly from Lotharek’s homepage. I should cost around €100, but I’ve seen “unofficial resellers” on eBay selling them for €150-200 – that’s a scam.
  • 5.25″ to 3.5″ adapter bracket, like this (I already had one from a computer chassis)
  • 4 pin Molex to floppy power adapter, like this (I had one lying around, probably included with a PSU)


First thing to do is to up open up the EII, which is a very simple process. Just a couple of standard Philips screws at the back and underneath. Then take the top of. Also locate the 4 screws that attaches the “floppy tower” to the chassis to remove it. 

At the middle of the main board, above middle C, a flat cable is folded, then going to the left, under the floppy tower and up to the drives. Remove this cable and use it as a model for the new cable.

Making the new cable

Prepare the flat cable by removing 6 of the wires to “convert” it from a 40 pin to a 34 pin flat cable. Then fold it at the exact same places and put the connectors at the same place, with one big difference – where the original cable has a 5.25″ for the upper drive, replace this with a 3.5″ connector. I used a vise to evenly squeeze the connectors to the cable. Make sure you orient the connectors the right way. Look for a little plastic piece between the 2nd and 3rd pins on the 5.25″ connector.

Swapping the faulty 5.25″ drive

The lower floppy drive didn’t want to load a disk that I know worked in the upper floppy drive.  Therefore I swapped them and carefully set their jumpers right. Now the lower one worked, but not the upper. Perfect, since my intention is to keep a working 5.25 floppy in the lower position and the floppy emulator in the upper position.

The faulty floppy drive with serial no 143922. Maybe it just needed cleaning, I don’t know –  I’ll keep it as a spare or something. It’s amazing the upper one works after 30 years…

5.25″ adapter and HxC metal work and jumper

I’ve used the HxC in lot’s of different samplers, and it has never properly aligned with the machine I’ve put it in. It always extends a couple of millimeters outside. So I decided to modify the HxC by drilling new holes in its metal chassis. For this I used 2.5 mm cobalt drill and used the adapter as a template. I chose this particular adapter since its pattern on the plastic matched the EII best.

Also set the jumper on the HxC to first position, as in the photos.

Floppy power adapter

For power to the HxC, a Molex to floppy power adapter was needed. Luckily I had a few of these lying around, probably included with some PC power supply, but never used. They can easily be found on eBay for a dollar or two. It’s simply connected to the Molex power connector that was previously connected to the now removed 5.25″ floppy drive.


Simply reassemble the EII the other way around!