Abstract: An electronic checkbook and method for using it. The checkbook comprises upper and lower parts which fold together when not in use. The lower part receives on its upper surface a booklet of checks. A digitizer is hingedly connected or fixed to the remainder of the lower part and operates as a keyboard in one mode when placed above the check booklet, and can be placed beneath the top check of the booklet and used in a second mode as a means for inputting signals to the remainder of the device representing information written on the check. The lower part of the checkbook also includes other elements of the device including a microprocessor, a power supply and a smart card reader/writer. The upper part includes a display screen upon which checking account information appears during use of the electronic checkbook. The method of use of the checkbook provides maintenance of a record of transactions in the account, including addition of deposits and subtraction of checks drawn on the account.

Abstract: A system for transmitting data characters from a communication channel to a datascope for displaying the data characters on a CRT screen includes a plurality of switch members settable to a position for identifying a predetermined source of the data message to be displayed. When a data message is transmitted over the communication channel, a plurality of comparator circuits detect the start of the data message and the source of the data message. Logic circuits add end of message characters to the data message and identify a character in the data message to be highlighted on the CRT screen when a collision occurs between two remote sources of data messages which are attempting to transmit a data message over the communication channel at the same time.