I will resume the discussion of this post if it is still possible.
For this pencil 2 computer, information is scarce, except that it would be a colecovision with an added keyboard and a different bios (to simplify what I found on the web).
Not having the coleco adapter, I would like to install a second coleco bios on this machine, either in a single eprom (including the two pencil bios - coleco), or by adding a second eprom connected to the machine's motherboard.
A switch switch would allow you to choose the bios before turning on the computer.
Does anyone have any advice / information for me please?