A "crazy" or not so crazy iead?! Turning a computer CDROM into a CD-player! This is funny stuff!!!
The price of, especially DVDs nowadays are ridiculous (low), so why spend the same money on an "as new" CDROM and a special controller from China?
The simple answer is - Because it's fun!
Many years ago, we got in touch with a guy in Thailand, or a Thai guy in Canada, cannot remember. He had developed such an interface and, in a groupbuy, delivered a bunch to us in Sweden.
Now it's a matter of finding a suitable bouse (I have come up with something that may work. A PSU - a scrapped PSU for an external HDD is perfect, especially it it supplies all voltages, +5V, +12V. I got one.
Finding a CDROM may be harder these days and not all CDROMs seem to "listen" to the commands given by the controller. DVDs may also work, but it's a matter of trial and error.