• Please review our updated Terms and Rules here

1993 Sony CD Caddy CD-ROM Drive Proprietary Interface SLCD (40-pin NON IDE)


New Member
Nov 8, 2013
Rhode Island, USA
Hello everyone,

I've got a bit of a problem. I'm in the process of getting a piece of automotive diagnostic equipment working again. Specifically it's a Jaguar PDU, or Portable Diagnostic Unit. The unit is a touch-screen diagnostic computer that interfaces with a "base station" which charges the batteries in the unit, and sends diagnostic software from the CD-ROMs to the PDU to store in it's memory while you're at the vehicle.

The problem is that the CD-ROM drive (Model # CDU-535-01) is a Sony unit from 1992/1993 that uses Sony's proprietary 40-pin SLCD "Sony Low Cost Drive" Interface. This drive uses a standard 40-pin IDE connector but is not IDE compliant. It is not SCSI either. On a desktop PC, you'd have to have the proper (bundled) interface card. This is similar to Sony's 34-pin interface.

The drive isn't working. After putting the CD-Caddy in the drive, it sucks it in like it should, but after spinning the disc three times over about 10 seconds, it ejects it out. It does it for every CD-ROM I have for the unit, with all different caddies. I've cleaned the lens of the pickup, and it's fine, everything is moving like it should when a CD is installed. The internals are clean and dust free, but it just doesn't want to recognize and read a CD-ROM anymore.

I'm trying to upgrade the base station to use a modern IDE drive. Is there any way to adapt a conversion IDE cable to convert the pins of each interface to match? I found a pinout for Sony's 34-pin interface and most, if not all pins look compatible with those of a typical 40-pin IDE interface.

I cannot seem to find a pinout for the 40-pin SLCD interface. Would anyone have any information on this? I found another person with this same diagnostic unit, however, he didn't have any base station at all. He had to make one of his own that provided power to the PDU and interface an IDE CD-ROM drive to the PDU unit. I've inquired with him as to how he successfully did it.

Here's Sony's Owners Manual for the drive/

If I could adapt the SLCD interface to an IDE compatible one, that would work well as I could use a modern reliable drive. I did, however, find a Sony CDU-6250, which is a 2-drive External CD-ROM drive that uses two CDU-535 drives in a double-bay enclosure. I'm hoping at least one of the drives is in good working order...

Any ideas?

Here's a pic of the unit with it's base station and Sony CD-Caddy Drive: