Information processing system

An information processing system comprising:

• an arithmetic processing unit and an external memory storage including a storage medium for storing data compressed by coding,
• the arithmetic processing unit and the external memory storage being detachably connected,
• the arithmetic processing unit having,
• a CPU for outputting an address code indicating an address area for storing the compressed data to a CPU address bus,
• a main control section for detecting an address code sent from the CPU,
• a run length counter, and
• a run data register;
• and
• the external memory storage having,
• a ROM address counter on which the initial address code position corresponding to an address area storing the compressed data in the storage medium is set, when the main control section detects the address code,
• a shift register in which the compressed data read from the address position of the storage medium corresponding to the address code set in the ROM address counter is set for sequentially shifting and outputting the compressed data,
• a ROM read control section for controlling to forward the initial address code position set to the ROM address counter one by one;
• a shift register control section for controlling the shift operation of the shift register, and
• a decoding table for using the output of the shift register as an address and outputting the run length and run data corresponding to the address,
• wherein the run length outputted from the decoding table is set to the run length counter and the run data is set to the run data register with control of the main control section, and
• the run data register sends the set run data to the CPU, while the run length counter subtracts the set run length one by one until the set run length becomes 0.

An information processing system comprising:

• an arithmetic processing unit and an external memory storage;
• the arithmetic processing unit and the external memory storage being detachably connected, and
• the external memory storage having,
• a CD-ROM for storing the data compressed by coding and a decoder on the side of a cartridge for storing the decoding table corresponding to the data coding, and
• the arithmetic processing unit having,
• a CD driver for reading the data stored in the CD-ROM;
• a CD controller for performing the error correction of CD-ROM standard to the read data, and
• a decoder on the side of the arithmetic processing unit for decoding the error corrected data from the CD controller referring to the decoding table of the decoder on the side of the cartridge.

A cartridge for use with a main data processing unit comprising:

• means for detachably connecting to said main data processing unit;
• means for storing and retrieving compressed data, said compressed data being restorable to
• an original binary data using first and second data decoding processes;
• and
• means for carrying out said first data decoding process,
• wherein said second data decoding process is left to be carded out by said main data processing unit.

A data information storage and decoding system comprising:

• a main data processing unit comprising:
• means for detachably receiving a data cartridge;
• means for transmitting a data readout request to said data cartridge;
• second stage data decoding means for receiving a first stage decoded data and converting said data to uncompressed binary data, and communicating said uncompressed binary data to a central processing unit;
• and
• a data cartridge comprising:
• storage means for storing compressed data;
• means for reading out requested compressed data according to said data readout request;
• first stage data decoding means for receiving said requested compressed data and converting said requested compressed data into first stage decoded data;
• and
• means for communicating said first stage decoded data to said second stage decoding means of said main data processing unit.