Nonvolatizing DRAM

In order to be useful, every computer must be able to preserve its program in the absence of power. Likewise, it is valuable to be able to capture data in real time and store it in nonvolatile memory for future referenced. Although static RAM is available with a built-in lithium energy source and control circuitry to make its power uninterruptible, thereby solving volatility problems, the same technique when applied to dynamic RAM has had limited acceptance because of the higher power consumption and the complexity of the overhead control circuitry. Low-power DRAMs and the introduction of Dallas Semiconductors integrated controllers now make nonvolatile DRAM very practical.