I put an old PATA HDD drive in as the slave, it will not detect it, the same with the old PATA CD-DVD drives.
I connected converter boards to each device, to allow for the use of the SATA connector cables.
Try configuring each PATA drive to CS (chip select) or MA (MAster).
Converter boards vary in compatibility, but I know the Marvell based boards for PATA drives work well, as do the bidirectional converters based on a Jmicron or Sunplus chip.
Is the power cable attached to the converter?
If you have bidirectional converters, are you using the correct SATA connector, as one is for SATA drives, the other for SATA controllers.
Many converters have undersized PATA sockets that are very easy to attach incorrectly.