How many SATA ports on iMac Intel 21 EMC 2428 entry level?

To clarify a bit: in addition to one SATA port for the optical drive, there are two SATA ports for the hard drives - one for the platter hard drive and one for an SSD. Both have proprietary power connectors on the logic board, but they both use standard SATA data connectors. We haven't gotten around to testing it yet, but I've been interested in using a splitter to turn one of the SATA power cables into two. I think you'd have to modify the optical drive cable because the hard drive power cable reportedly sends temperature signals from a sensor on the HDD to the logic board instead of using an external sensor. I'm not sure if splitting that power cable would cause any problems with the fans ramping up or not. Since the optical drive uses an external temperature sensor, It seems that splitting that cable would be the safer option. The only problem is that the connector on the optical drive side of that cable is SATA power and data molded into one connector. My solution would be to tuck that connector behind the logic board near the optical drive SATA connections and to use a short female to male SATA data cable to hook up the data side. Then use a splitter like this to split the power connector to give juice to both the optical drive and the SSD. Then you'd just use a standard male to female SATA data cable to connect the SSD to the logic board. Let us know if you try it or are successful, I'm interested in how something like this would work.

There are Three SATA Ports

also the entry level!

I have mount today secondary ssd to my entry level iMac 21.5