Before you yell at me for wanting too much from the IPACS devs, hear me out. I see videos on YouTube of what looks to be a functioning FMC in the Dash 8 Q400 from about 2 to 3 months ago. Ever since the HUD was added to the aircraft, the FMC is different. Was the FMC once a functioning piece of equipment or does it just look different now?
I have started work on the CDUs (interaction menus with the already existing FMS) in the A320, B747, Learjet and Q400. The A320 MCDU ist by far the most advanced implementation of these yet and is already working well and my plan is to have each of the CDUs operational eventually. E.g. also the ones in the c90 and b737.
But this takes away a lot of time, a lot of research to find out when which field is shown, how each of the pages looks like on ground, before takeoff, during takeoff, clb, crz, des, appr, ldg, rollout..., when which field is editable, its value range, what is the exact pattern you need to enter, e.g. 123. or 123.0 or 123.0/ etc.
Current status of the q400: it was a static image of the FMS before, I now send it text but it just shows how far I got so far. I have a version that shows more text but that requires a lot of changes in the autopilot, FMS and CDU code and that is why I have not merged it into the public release yet. It would put a lot of code into an untested state which I don't want.
I am afraid that it will take a while before you see a fully functional CDU. It's not something that can be done fast.