Architecture for 21/2 inch diameter single disk drive

A disk drive responsive to a host computer, comprising

• a molded plastic base plate having a two and one-half inch form factor;
• a molded plastic cover snap-fit to said base plate to provide a oontrolled environment between said base and said cover;
• a disk rotatably mounted on said base plate in the oontrolled environment, said disk having a plurality of concentric tracks, a landing zone, and a diameter of less than approximately 2.6 inches;
• means for reading information from and writing information on selected ones of said tracks of said disk;
• means for positioning said transducer means over selected tracks on said disk by closed loop tracking;
• and
• parking means, supported by said magnetic means, for magnetically interacting with said actuator arm to park said transducer means over the landing zone of said disk.

A disk drive responsive to a host computer, comprising:

• a molded plastic base having a two and one-half inch form factor;
• a molded plastic cover attached to said base plate by snap-fit, said cover complying to the shape of said base when attached to said base;
• a gasket provided between said base and said cover to provide a sealed environment isolated from ambient Pressure between said base and said cover;
• a disk having a diameter of less than approximately 2.6" rotatably mounted on said base plate in said controlled environment, said disk having a plurality of concentric tracks;
• a head for reading information from and writing information on said disk;
• an actuator arm pivotably supported on said base plate, said actuator arm having a first end for supporting said head and a second end disposed on the opposite side of said pivotable support from said first end;
• a magnet structure attached to said base and formed of a permeable material, said magnet structure including top and bottom plates each having first and second ends and a spacer for separating said first ends of said top and bottom plates, said second end of said top plate having a portion which extends at an angle from the remainder of said top plate to join said base plate and separate the second ends of said top and base plates;
• magnetic means, supported by said magnet structure, for providing a magnetic field;
• a coil, supported by said second end of said actuator arm and lying in a plane substantially parallel to said disk, for passing a current in the magnetic field;
• and
• control means for providing current to said coil in response to information read by said transducer means to position said head over selected tracks on said disk by closed loop tracking.