The platter shown is one of 10 that constituted a "pack." Each platter stored 5 MB per side (10 MB per platter) and with ten platters in a pack, the total capacity of the pack was 100 MB. The data rate was 806 KB/s with a seek time of 50 ms. The two rings near the outer edge are the remains of a head crash, where the read / write head actually crashed into the platter and gouged away the magnetic surface rendering the platter useless. This is where the tearm "hard drive crash" came from.

The read/write head and arm is shown on top of the platter. The arm is stainless steel so that it would not be influenced by the magnetic fields of the disk and read / write head. The black, vertical line on the rectangular plastic piece on the end of the arm is the actual read/write head. The width of the line is the actual width of a track on the platter.

Donated by John Wayne.