Abstract: A memory package for storing data and capable of being added to or replaced while being provided with a battery backup in computer systems which can be mounted with a plurality of said memory packages. A memory package also has a function to reduce power consumption of the battery backup to a minimum, when the memory package with battery backup is inserted into the computer system without the main power being applied. Consequently, even if additional memory packages are inserted which require battery backups, only a weak current need be supplied from the backup power supply so that the battery will not run down after a short time. The memory packages can therefore be added and replaced while still storing data internally and the memory capacity can be changed. Also, a memory system is provided including a power supply supplying power supply lines connected to the memory packages. Diode and/or surge protection arrangements are also provided to facilitate hot line insertion and removal.

Abstract: A memory package for storing data and capable of being added to or replaced while being provided with a battery backup in computer systems which can be mounted with a plurality of said memory packages. A memory package also has a function to reduce power consumption of the battery backup to a minimum, when the memory package with battery backup is inserted into the computer system without the main power being applied. Consequently, even if additional memory packages are inserted which require battery backups, only a weak current need be supplied from the backup power supply so that the battery will not run down after a short time. The memory packages can therefore be added and replaced while still storing data internally and the memory capacity can be changed. Also, a memory system is provided including a power supply supplying power supply lines connected to the memory packages. Diode and/or surge protection arrangements are also provided to facilitate hot line insertion and removal.

Abstract: A memory package for storing data and capable of being added to or replaced while being provided with a battery backup in computer systems which can be mounted with a plurality of said memory packages. A memory package also has a function to reduce power consumption of the battery backup to a minimum, when the memory package with battery backup is inserted into the computer system without the main power being applied. Consequently, even if additional memory packages are inserted in computer systems installable with memory packages having battery backups, only a weak current need be supplied from the backup power supply so that the battery will not run down after a short time. The memory packages can therefore be added and replaced while still storing data internally and the memory capacity can be changed. Also, a memory system is provided including a power supply supplying power supply lines connected to the memory packages.

Abstract: A memory package for storing data and capable of being added to or replaced while being provided with a battery backup in computer systems which can be mounted with a plurality of said memory packages. A memory package also has a function to reduce power consumption of the battery backup to a minimum, when the memory package with battery backup is inserted into the computer system without the main power being applied. Consequently, even if additional memory packages are inserted in computer systems installable with memory packages having battery backups, only a weak current need be supplied from the backup power supply so that the battery will not run down after a short time. The memory packages can therefore be added and replaced while still storing data internally and the memory capacity can be changed.

Abstract: A memory system includes a flash memory having a plurality of individually erasable physical blocks, table section for holding the relationship in correspondence between the logical blocks allocated by the allocation section and the physical blocks first counting and managing section for counting and managing write counts of the respective logical blocks, first classifying section for classifying the logical blocks into a plurality of groups on the basis of the respective write counts of the logical blocks, erasure section for erasing data in a physical block allocated to a logical block to produce a free physical block, second counting and managing section for counting and managing the erasure counts of the respective physical blocks, second classifying section for classifying the physical blocks into a plurality of groups on the basis of the respective erasure counts of the physical blocks, control section for allocating the respective logical blocks to the physical blocks; and managing section for managing

Abstract: A memory system includes a flash memory having a plurality of individually erasable physical blocks, table section for holding the relationship in correspondence between the logical blocks allocated by the allocation section and the physical blocks first counting and managing section for counting and managing write counts of the respective logical blocks, first classifying section for classifying the logical blocks into a plurality of groups on the basis of the respective write counts of the logical blocks, erasure section for erasing data in a physical block allocated to a logical block to produce a free physical block, second counting and managing section for counting and managing the erasure counts of the respective physical blocks, second classifying section for classifying the physical blocks into a plurality of groups on the basis of the respective erasure counts of the physical blocks, control section for allocating the respective logical blocks to the physical blocks; and managing section for managing

Abstract: A semiconductor memory is provided which includes an electrically rewritable non-volatile semiconductor memory. A data control circuit is also provided which includes an ECC circuit and which operates to control the writing and reading operations of data to and from the non-volatile semiconductor memory. In order to temporarily hold data which is to written into the non-volatile semiconductor memory, a volatile cache semiconductor memory is utilized. This volatile cache semiconductor memory has a storage capacity which is equal to or less than the storage capacity of the non-volatile semiconductor memory itself. A data control circuit is also provided to read out data from the non-volatile semiconductor memory and the volatile cache semiconductor memory, and to transfer the data from the volatile semiconductor to the non-volatile semiconductor memory.

Abstract: A semiconductor storage including a main flash memory, a volatile write cache, a data control circuit, an alternate flash memory and a power supply. This arrangement permits the use of a smaller write cache in comparison with the use of a non-volatile memory, and also provides decreased capacity of the write cache, permitting high-speed access and long-life.

Abstract: An information recording and reproducing apparatus comprises a 31/2 inch hard disk drive, a semiconductor memory connected to the 31/2 inch hard disk drive for exchanging data, and a battery used to trasfer data in the semiconductor memory to the 31/2 inch hard disk drive when a power supply is shut off, all of which are accommodated in a housing of the same outer dimension as that of a 51/4 inch floppy disk drive. The information recording and reproducing apparatus is replaceable with a conventional floppy disk drive and can attain high speed accessing.