This is a Psion MC400, a relatively rare laptop from 1989. It was very advanced for the time, with a GUI, a trackpad, a multitasking OS and entirely solid-state storage. It even ran for about 75 hours from 8 AA batteries. But they were expensive and never sold well. I've always wanted one, and finally got hold of one a few months ago. Thing is, a blotch appeared in the LCD and it's getting bigger. I have no idea what it is, but could it be leaking or something? I've been very careful with it and it's not had any knocks as far as I know. Apparently the LCD is a retardation film type. Anyone got any ideas what it is? I've attached an image of the machine and a close up of the blotch, which didn't come out all that well, but gets the idea across.