I'm searching for some big device (22 inch) on which can draw, write and load some presentation file. Want to replace pan and paper with some modern device. Let's say that want to make instruction of physics for classroom, and instead of writing on whiteboard to write on that device (which have big advantages cause can save those materials and use it next time, also can be improved next time, etc...).
Something bigger than tablet, like in this video (what device is used in video?)
Do you have some idea what to buy for those purpose?