3000 is a
CP/M keyboard to use with FDD3000 but actually is another computer. It
have ROM, RAM, Timex SCLD, Z80A and the FDD interface built-in.
It attach to the same cable, that the interface uses (so, when you have TT3000 connected, you can't use a computer nor the interface). A video composite monitor must be connected to the video composite jack in FDD3000 rear (it cannot use a TV because it doesn't have the TV modulator).
TT3000 generates the video signal, send it throuth the cable, to
FDD3000. In FDD3000, the video signal goes directly to the video composite jack.
This was made to prevent two cables in TT3000.
With TT3000 CP/M works in 80 colunns.