A device generates a random bit sequence with a digital ring oscillator circuit comprising logic components. According to one feature, a control portion monitors a characteristic of information read from the storage medium, and can take action to reduce the likelihood of non-recoverable errors based on the characteristic. The network hang may be detected when the user tries to terminate the application. A hash generator generates hash values that are determinative of the page indication locations that are populated with the page indication values. 010 width varying by less than 0.