Patent GB-1508441-A (GB)
Title: Electronic data collection devices
IPC: G06F17/40
Filed: 1975-03-23
Abstract: 1508441 Selective signalling AZURDATA Inc 23 March 1975 [23 April 1974] 3004/75 Heading G4H A hand-held portable electronic data collection device comprises an integral power supply, entry means for producing coded data character and control signals, a multi-line random-access memory addressable in accordance with the control signals to store the data signals, and a visual display for displaying characters corresponding to the data signals stored in the memory. As disclosed, the entry means is a keyboard having keys for the numerals 0-9 and six control keys (see below). The lines of the (recirculating) memory each have up to four fields, which may be contiguous or with gaps between them or overlapping, a diode matrix ROM (which may be replaceable) holding the start and end addresses of each field. The (multicharacter 7-segment) display shows the contents of the currently-addressed field in the currentlyaddressed line, the line number. The location of a cursor indicating the currently-addressed character (in the form of a lighted dot by the character position), and which of the four fields is being addressed (by means of two dots, one being lit continuously or flashing). At power turn-on, the memory is reset by having a clear code written into each character position, then the first character of the first field of the first line is addressed. The numeral keys can be used to enter a character into the addressed field, the cursor automatically moving along as each character is entered (so that successive positions are written into). The six control keys are: left and right cursor move keys (for a tab function), up and down line move keys (to address the same field and character position in the preceding or succeeding line respectively), a clear key (to clear the currently-addressed character), and a field advance key (to advance to the first position of the next field in the currently-addressed line). A manual switch can be used to ensure availability of all four fields for data entry, rather than just the first two, but must be operated anew for each line, and during scanning (see below) memory reset (see above) and read-out to the formatter (see below) all four are used anyway. If the field advance key is used to attempt to advance beyond the fields to be used, the system loops back to the first of the fields to be used. The line move keys produce one move per depression, except that depression of more than a certain duration will cause continuous production of moves. The field advance key is similar in this respect, but with the long depression causing scanning of the whole memory field by field until the clear key is pressed. Key actuations are encoded by clocking a binary counter until its decoded output reaches the actuated key. To conserve power, a mercury tilt switch cuts off power from the display when the device is disposed downwardly. An external battery, when connected, powers the device and trickle charges an internal battery which powers the device in the absence of the external battery. If the battery voltage falls too low, all the cursor display dots are blinked on and off continuously. The device can be plugged into a formatter which calls for successive characters from the memory to read out its contents, converts to ASCII or EBDIC, inserts carriage return and line feed codes at the end of each line, can insert space and line feed codes at preselected character counts, adds parity, and serializes the message for transmission to a central computer and/or printer. The memory can be loaded as desired via the formatter from the computer.