Abstract: An improved tape cartridge having two tape packs mounted for rotation in a housing; an endless elastic belt mounted about a first and second roller to engage the tape packs on their periphery; said first roller rotatable about a stationary axis; said second roller being a floating belt-guide roller urged by the tension of the belt against the two tape packs with the belt squeezed between each pack and said first roller, said floating belt-guide roller having a draft on the outer surface to form a frusto-conical shape; means for driving said belt whereby as said belt is driven the belt tends to climb to the high side of the floating roller urging the central hub of the floating belt-guide roller to point contact with the base plate of the housing.

Abstract: A device and method are disclosed for testing the abrasion quality of a magnetic recording member to cause recording head wear. A magnetic recording member to be tested is moved past a dummy recording head, the smoothness of which has been determined before the head is contacted with the magnetic recording surface. After a predetermined contact between the dummy head and the tape, the smoothness of the head is again determined which is a direct function of the abrasion characteristics of the tape. The smoothness of the dummy head is determined by means of a non-contact photonic sensor which converts reflective light from the surface of the head into a specific voltage output.