Pioneer DVR-K15 Question

Could anybody please tell me if the Pioneer DVR-K15 is configured as a CSEL (slave) drive or as a master drive? It’s slim drive

There is nothing to configure. Just plug it in.

I would suggest contacting the place you plan to buy before purchasing. Most (if not all) are OEM, and will be configured to the spec of the buyer (the place you are buying from, or the place that THEY bought from).
That being said, most notebook drives are configured master or cable sel IME.

Best of Luck,
-Evan-