I have a Swiss Gear back pack. Good zippers, well thought out in terms of pockets and strong. Has a padded spot for lap top, little pocket for an e-reader, another for your passport. It's big enough for a few days of clothes.
I think they label it as a computer back pack. I think amazon has them for around $60-70.
990SMT, 640A, TXC450, TE510, ATC350X, ATC200ES, 550MXC, BW200. Need more space in garage.