I think you must be confusing it with one of the later Powerbooks with passive matrix screens. I have a Portable in the attic somewhere, and I used to boot it

I think you must be confusing it with one of the later Powerbooks with passive matrix screens. I have a Portable in the attic somewhere, and I used to boot it up and play around with it a bit. The screen was dark (no backlight) but very crisp and relatively smooth for the era.