this must be the place....goin strong , yeah baby!!!

Thursday, February 17, 2011

Resurrecting an Ensoniq EPS classic sampler

Join me, for a journey into the world of vintage music electronics repair and modification...

Our subject, the Ensoniq EPS.
Don't know it? Sure you do!!! Ever heard Wu-Tang's 36 Chambers? You've heard this keyboard. It was the precursor to the uber-popular ASR-10.
It's a very characteristic 13-bit sampler beamed to us from 1988. Low RAM in this one (480k) means you gots to get real creative.
Anyway, I was given this keyboard, and immediately dug it. I already had a soft-spot for the ESQ-1, and this is basically like it's sampling brother.
The only problem with these old machines though, is that floppy disks are not much fun, the particular ones for the EPS are very hard to find (DD, not HD!), and they will eventually fail. The HxC Floppy Emulator steps in to replace your thousands of floppies with one, easy to find SD card.

The process:
I backed up all my EPS disks via OmniFlop. This creates a RAW img file, which, as far as I know, is just a byte-for-byte (or close to that) copy of the diskette. The beauty of this format is that the host machines don't need to be able to read it, they just copy the raw data off it. The problem is, you don't know if it's working til you've tried it. I did not anticipate this, and thought the software would read my *.img files easily...not so.
So in the HxCFloppyEmulator software, I can't do 'batch convert' (that expects *.efe files...i've got *.img raw files), I had to do "Load Raw image":
- Load Raw image
- You have to change the settings in this menu.
For 819200 byte images, use these parameters:
Sector per track = 10
Sector ID start = 0
GAP3 lenght = 40
Anyway, that converted all my floppies to images, and at that point, I just hoped it would work.
Finally found the EPS service manual, which helped me remove only the screws I needed to remove the disk drive.
Here are the instructions from the service manual:

Replacing the EPS Disk Drive
1. Remove all cables connected to the EPS, including the power cable.
2. Remove the four (4) screws that fasten the control panel with a 2.5mm hex wrench.
NOTE: These are machine screws.
3. Turn the unit over, top down, and remove the four (4) screws that attach the wheel assembly to the case. See Figure 12 for location of screws. Return the unit to an upright position and raise the control panel. Carefully lift the wheel assembly out of the case.
4. Disconnect the two cables from the Disk Drive, paying particular attention to the polarity. (See Important things to know - the disk drive, page 2).
5. Remove the four (4) screws and star washers that attach the disk drive to the wheel assembly.
6. Carefully slide the Disk Drive out of the wheel assembly. Remove the two (2) screws and star washers that attach the metal plate to the bottom of the disk drive.
etc, etc...

Got that out, got the floppy emulator in, powered up, and CRAP! it WORKED. Couldn't believe it. Scrolled over to the disk image for the OS, and the sumb*tch loaded up like nothing was wrong.
I made the above video while I was doing the upgrade, and then I created the soundtrack from the demo disks that came with the EPS.
So if you've got an old sampler, and floppy disks are holding you back, get over it.

1 comment:

  1. i need someone in michigan who can get by ensoniq EPS 16+ working again... it used to work just fine with my ZIP drive and now it wont even boot from floppy - please help -