I bought a Texas Instruments TI99/4A

Like the title says. However I don’t know how to connect the diskdrives.

I bought a very complete TI99 set from a woman whose (late -i think) husband worked for Texas Instruments.
The thing is, that I don’t know how to connect all the peripherals. I know how to connect the tape, tv. But there’s also:

– a RS232 module
– a Memory expansion
– 2 diskdrives
– diskcontroller

The interesting thing is the 2 diskdrives + controller, see attachment:
I connected the diskdrives with a flatcable to the controller. The controller has a (wooden) connector that should connect to the right port on the TI, but there are two catches:
1. the connector doesn’t fit easy, so I guess I have to put either the memory expansion or the RS232 device between de disk controller and the computer
2. how does the floppydrive get its power? Should I connect a psu to the wooden connector?

It’s puzzling.
Any help is greatly appreciated.