Card reader system with improved interface

A card reader adapted to interface with a remote control processing unit, comprising:

• a. reading means for reading cards and generating data signals;
• b. condition means for generating condition signals representative of predetermined conditions of said card reader;
• c. operation means, for receiving operation commands whereby said card reader performs predetermined operations;
• d. transmission means connected to said reading means and said condition means for generating information words in a form suitable for transmission to said central processing unit, said transmission means having at least one adaptable component whereby at least one of said information words may be altered, said transmission means also having
• i. means for generating information words representing card reader data, said card reader data words having trailing zeros suppressed,
• ii. a buffer for storing data read from a card, and
• iii. recirculation means for recirculating said data through said buffer as said data is transmitted;
• and
• e. receiving means connected to said operation means for receiving commands from said central processing unit and generating signals for controlling the operation of said card reader, said receiving means having at least one adaptable component whereby at least one of said commands may be altered.

A card reader system providing for the interfacing of a plurality of card reader units with a central processing unit, comprising:

• a. a central processing unit;
• b. a plurality of card readers for reading cards, adapted to communicate with said central processing unit;
• c. communication means for providing communication of information between said card readers and said central processing unit;
• d. each of said plurality of card readers having
• i. address means for receiving address signals from said central processing unit and for selectively enabling and disenabling card reader operation depending upon whether such card reader has been addressed;
• ii. status word means for generating status words representative of operating conditions of said card reader;
• iii. data word means for generating data words representative of data from said cards, said data word means having means for suppressing trailing zero words;
• iv. means for converting said data words and said status words from a first form to a second form suitable for transmission to said central processing unit;
• e. said data word means having a buffer for storing data as it is read from a card and recirculation means for recirculating said data through said buffer when said data is read out of said buffer, and means for retransmitting data read from said card reader with trailing zero suppression.

A card reader system providing for the interfacing of a plurality of card reader units with a central processing unit, comprising:

• a. a central processing unit;
• b. a plurality of card readers for reading cards, adapted to communicate with said central processing unit;
• c. communication means for providing communication of information between said card readers and said central processing unit;
• d. each of said plurality of card readers having
• i. address means for receiving address signals from said central processing unit and for selectively enabling and disenabling card reader operation depending upon whether such card reader has been addressed;
• ii. status word means for generating status words representative of operating conditions of said card reader;
• iii. data word means for generating data words representative of data from said cards, said data word means having means for suppressing trailing zero words;
• iv. means for converting said data words and said status words from a first form to a second form suitable for transmissin to said central processing unit;
• e. said address means having storage means for storing a predetermined address chosen from a plurality of respective addresses, and circuitry for decoding a multi-bit address signal transmitted from said central processing unit, said circuitry comprising means for decoding when the four most significant bits of said address signal are ones and when the four least significant bits correspond to address information in said storage means;
• and
• f. output transmit means for outputting data in said second form from said card reader to said communication means for transmission to said central processing unit.

A card reader system providing for the interfacing of a plurality of card reader units with a central processing unit, comprising:

• a. a central processing unit;
• b. a plurality of card readers for reading cards, adapted to communicate with said central processing unit;
• c. communication means for providing communication of information between said card readers and said central processing unit;
• d. each of said plurality of card readers having
• i. address means for receiving address signals from said central processing unit and for selectively enabling and disenabling card reader operation depending upon whether such card reader has been addressed;
• ii. status word means for generating status words representative of operating conditions of said card reader;
• iii. data words means for generating data words representative of data from said cards;
• iv. means for converting said data words and said status words from a first form to a second form suitable for transmission to said central processing unit;
• e. receiving means for receiving information communicated to it from said central processing unit;
• f. output transmit means for outputting data in said second form from said card reader to said communication means for transmission to said central processing unit;
• and
• g. mode means for enabling when said output transmit means is operable and when said receiving means is operable.

A card reader apparatus adapted for interfacing with a central processing unit, comprising:

• a. address means for receiving address signals from said central processing unit and for selectively enabling and disenabling card reader operation depending upon whether such card reader has been addressed;
• b. status word means for generating status words representative of operating conditions of said card reader;
• c. data word means for generating data words representative of data from said cards;
• d. output transmitting means for transmitting said data words and said status words from said card reader, said transmitting means having means for suppressing trailing zero data words;
• e. retransmitting means for retransmitting data words, said retransmitting means having means for suppressing trailing zero data words.