Memory modules address the growing gap between main memory performance and
disk drive performance in computational apparatus such as personal
computers. Memory modules disclosed herein fill the need for
substantially higher storage capacity in end-user add-in memory modules.
Such memory modules accelerate the availability of applications, and data
for those applications. An exemplary application of such memory modules
is as a high capacity consumer memory product that can be used in
Hi-Definition video recorders. In various embodiments, memory modules
include a volatile memory, a non-volatile memory, and a command
interpreter that includes interfaces to the memories and to various
busses. The first memory acts as an accelerating buffer for the second
memory, and the second memory provides non-volatile backup for the first
memory. In some embodiments data transfer from the first memory to the
second memory may be interrupted to provide read access to the second
memory.