This. You cannot charge four cells in serial without the right balance charger or you could end up with one dead cell and three good ones and no output.
The Code Club that I help run is usually for 9-11 year-olds, but we have had one (barely) 8 year old join and she is doing really well.
IBM did them first. Called them Microdrives (I have one) even though Sinclair had already used the name for their dodgy tape loop drives (I had a couple of those too)
Ah, could be. In that case it is unlikely to be any use, especially not without a datasheet for the screen.