Tested and confirmed*
*on my system, which has had the controller port resistors removed & their connections bridged.
Pictured is a wireless IR keyboard with a built in trackball & 2 button mouse, that has a pair of old (pre-usb) ps/2 plugs.
When using that with the two "Total Control 5" adapters (pictured small plugs in the dreamcast), the receiver of the keyboard/mouse combo functions normally, and I was able to play Unreal Tournament with the unit successfully.
I sucked at it, because the mouse was spread across the keyboard, and the arrow-keys on this particular keyboard are stiff/sucky.
But, confirmed that it works.
There doesn't seem to be any power drain issues, as I played with a stock official controller in port 4 - for vmu access to the game, and played for over 30 minutes. The normal power drain issues didn't occur (vmu's not being registered, or random power-down of the system), but I'll be using this keyboard with PSO online play for a while to re-evaluate its long-term usage.
I have a pair of USB to PS/2 adapters coming in the mail shortly, and will be testing to see if current generation USB mouse / keyboards function normally, as I'm not happy with the stiffness of this Earthwalk keyboard. I read a report that someone had an optical mouse working with that "Total Control 5" adapter, and am curious to see if it can be replicated.
What I would really like to do is gut the transmitter out of the Earthwalk Keyboard and somehow put it in the japanese clear official dreamcast keyboard, and add the necessary power supply, so that its a semi-official wireless dreamcast keyboard. I then want to take a sega Saturn mouse shell, and build in the optical components out of a mouse, and if possible make it wireless, or possibly wired to the keyboard (a more likely scenario).
Does anyone here know if much of that is possible? I can take apart the keyboard and take some very high-definition pictures of the transmitter part of the pcb, if that would be at all helpful.
I'm not very good at electronics, and as in this case, I'm the guy that finds adapters. I really would like to put the transmitter and a power supply in my official keyboard, and also add the transmitting data from a mouse, but am not sure how.