A software implementation of a related idea on ordinary hardware is included in CryptoLib, a cryptographic routine library. The algorithm is called "truerand". Most modern computers have two crystal oscillators, one for the real-time clock and one for the primary CPU clock; truerand exploits this fact. It uses an operating system service that sets an alarm, running off the real-time clock. One subroutine sets that alarm to go off in one clock tick (usually 1/60th of a second). Another then enters a while loop waiting for the alarm to trigger. Since the alarm will not always trigger in exactly one tick, the least significant bits of a count of loop iterations, between setting the alarm and its trigger, will vary randomly, possibly enough for some uses. Truerand doesn't require additional hardware, but in a multi-tasking system great care must be taken to avoid non-randomizing interference from other processes (e.g., in the suspension of the counting loop process as the operating system scheduler starts and stops assorted processes).