What is a “Slim” IDE interface?

I recently purchased a DVD-ROM drive (Matsushita SR-8185-C) that was advertised as having an IDE/ATAPI interface, but when I received it, the connector was NOT the standard 40-pin…instead, it is a densely packed 50-pin connector that is only about7/8 inch wide. Also, there is no power connector on this drive, so presumably the power is supplied through this same connector. I’ve been told that this is a “Slim” IDE, but I can’t seem to get any more details about it. Can anyone tell me about this? Is this some kind of new standard? And how can I use this with my existing controller, or do I have to get a new controller? If so, what kind?

Thanks!