1. An information processing system comprising:
receiving means for receiving transmitted information, the information being coded or incomplete;
a recording medium, decoding information needed to demodulate the received information being recorded on said recording medium;
reading means for reading out the decoding information from said recording medium; and
demodulating means for converting the information received by said receiving means to a usable form using the decoding information read out by said reading means.

2. An information processing system according to claim 1, wherein said recording medium comprises a first area in which the received information is to be written and a second area in which the decoding information is recorded, and further comprising writing means for writing the information received by said receiving means in the first area of said recording medium.

3. An information processing system according to claim 2, wherein said recording medium comprises an optical disc and the decoding information is recorded in said optical disc in a form of pits having an uneven structure.

4. An information processing system according to claim 1, wherein a first identification code is included in the received information and a second identification code is recorded in said recording medium, and further comprising comparison means for comparing the first identification code of the information received by said receiving means with the second identification code recorded in said recording medium and instruction means for instructing said demodulating means to start the demodulation of the received information when the first identification code coincides with the second identification code in said comparison means.

5. An information processing method comprising the steps of:
receiving transmitted information, the received information being coded or incomplete;
reading out decoding information needed to demodulate the received information from a recording medium; and
demodulating the received information by using the read out decoding information to convert the received information to a usable form.

6. An information processing method according to claim 5, further comprising a step of writing the received information onto the recording medium.

7. An information processing method according to claim 5, further comprising a step of comparing a first identification code included in the received information with a second identification code recorded in the recording medium and wherein the demodulation of the received information is started when the first identification code coincides with the second identification code in said comparing step.

8. A method of distributing information, said method comprising the steps of:
transmitting a plurality of groups of information to a plurality of users, the groups of information being respectively coded in different code systems;
distributing a plurality of kinds of recording media respectively corresponding to the plurality of groups of information, decoding information needed to demodulate the respective groups of information being respectively recorded in the plurality of kinds of recording media;
reading out the decoding information recorded in one of the recording media; and
demodulating the group of information corresponding to the one recording medium by using the read out decoding information to convert the group of information to a usable form.

9. An information processing system comprising:
a host computer, said host computer providing coded software;
a first modem for transmitting the software provided by said host computer through a telephone line;
a second modem for receiving the software transmitted through the telephone line;
a recording medium, decoding information needed to demodulate the coded software being recorded on said recording medium;
a driving unit for reading out the decoding information from said recording medium; and
a personal computer for demodulating the software received by said second modem by using the decoding information read out by said driving unit to convert the software to a usable form.

10. An information processing system according to claim 9, wherein said recording medium comprises a first area in which the software is to be written and a second area in which the decoding information is recorded, and said driving unit writes the software received by said second modem in the first area of said recording medium.

11. An information processing system according to claim 10, wherein said recording medium comprises an optical disc and the decoding information is recorded in said optical disc in a form of pits having an uneven structure.

12. An information processing method comprising the steps of:
receiving coded software transmitted from a host computer through a telephone line;
reading out decoding information needed to demodulate the coded software from a recording medium; and
demodulating the received software by using the read out decoding information to convert the received software to a usable form.

13. An information processing method according to claim 12, further comprising a step of writing the received software in the recording medium.

14. A system for receiving a coded broadcast signal, said system comprising:
a receiving circuit for receiving a coded broadcast signal;
a recording medium, software needed to demodulate the coded broadcast signal being recorded in said recording medium;
a driving unit for reading out the software from said recording medium; and
a processing circuit for demodulating the broadcast signal received by said receiving circuit by using the software read out by said driving unit to transform the coded broadcast signal to a usable form.

15. A system according to claim 14, wherein the broadcast signal comprises a character broadcast signal, and the software comprises a program for transforming coded character codes into normal character codes or character code data.

16. A system according to claim 14, wherein said recording medium comprises a first area in which the broadcast signal is to be written and a second area in which the software is recorded, and said driving unit writes information received by said receiving circuit in the first area of said recording medium.

17. A system according to claim 16, wherein said recording medium comprises an optical disc and the software is recorded in said optical disc in a form of pits having an uneven structure.

18. A system according to claim 14, wherein a first identification code is included is the broadcast signal and a second identification code is recorded in said recording medium, and further comprising a comparison circuit for comparing said first identification code of the broadcast signal received by said receiving circuit with said second identification code recorded in said recording medium and an instruction circuit for instructing said processing circuit to start the demodulation of the information when the first identification code coincides with the second identification code in said comparison circuit.

19. A method for receiving a coded broadcast signal, said method comprising the steps of:
receiving a coded broadcast signal;
reading out software needed to demodulate the coded broadcast signal from a recording medium; and
demodulating the received broadcast signal by using the read out software to convert the coded broadcast signal to a usable form.

20. A method according to claim 19, further comprising a step of writing the received broadcast signal in the recording medium.

21. A method according to claim 19, further comprising a step of comparing a first identification code included in the broadcast signal with a second identification code recorded in the recording medium, and wherein the demodulation of the broadcast signal is started when the first identification code coincides with the second identification code in said comparison step.