I have acquired somehow a very interesting TI prototype. Unfortunately I do not really know the source but the Datamath museum has more information on it here: Texas Instruments Personal Learning Tool PLT SHH1.
The “PLT” comes from “Personal Learning Tool”. The OS inside seems to be a version of Linux.
The unit that is in my possession has a charger (6V DC) and a battery case which can accommodate 3 AAA batteries. Unfortunately the unit does not work with either the charger or the 3 AAA batteries.
The machine does turn on and seems to function if powered directly at the battery terminals with a lab power supply. The machine takes just under 200ma of current which an AAA battery should be able to provide, nevertheless with batteries it doesn’t work whereas with a lab power supply it does. I have not tried to explain this.
The ,machine still has the warranty sticker attached so I did not want to open it to look inside.
Please see some images of this unusual machine.