Abstract: The media labeling system makes use of human-readable and machine-readable label indicia to automatically identify of the media type contained within each of a plurality of data storage elements that have a substantially uniform external form factor. The machine-readable indicia includes a standard 3-of-9 bar code in addition to a unique bar and space code to provide error detection for damaged or partially obliterated labels, and to help low resolution bar code interpreters to distinguish the media type label from other label indicia present on the data storage element.

Abstract: A card reader maintenance system includes a card reader and a maintenance apparatus.

Abstract: A method of entering a hand-marked response into a system by altering a predetermined modified bar code symbol in a manner so that the bar code is rendered readable. In this manner, bar code reading devices can be utilized to detect the hand marked response. In an alternative embodiment, one of several potential responses may be marked and rendered non-decodable. A bar code reading device determines which of the several responses has been hand-marked by ascertaining which is non-decodable. Marking the response sheets may be aided by using an opaque template sheet or using a pressure sensitive overlay sheet.

Abstract: A method of obtaining and providing card identifying information from a data card presented in connection with a financial transaction, the data card having a magnetic stripe and an embossed region containing identifying information, the method being carried out in a data card terminal. The data card terminal is operative for gathering credit card or check information required for customer transactions at a point of sale. The method comprises providing a transaction risk parameter selectively indicative of a first or second level of transaction security to be provided for the data card terminal. In response to the transaction risk parameter indicating the first level of security, verified card identifying information is provided if either the first data record region or the second data region contains valid card identifying information. In response to the transaction risk parameter indicating the second level of security, a second level security check is performed.

Abstract: A system and method for testing bar code scanner window viability which determines whether the window is scratched or otherwise damaged enough to require replacement. The system includes a laser beam source. The laser beam passes through a window glass for scanning a bar code label. Light reflected from the bar code label passes through the window glass and is detected and converted into an electrical signal. Finally, a processor determines the bar code information from the electrical signal and determines whether the window glass is damaged enough that the bar code information cannot accurately be determined. The method determines the variance between the widths of the bars and spaces from a plurality of bar code scans and compares the variance to a predetermined threshold. The window glass is replaced when the threshold is exceeded.

Abstract: A card convey device includes a card convey unit, a punching unit, a counting unit, and a control unit. The card convey unit selectively conveys a card in a discharging direction and an opposite direction thereto. The punching unit punches the card which slows down, while the card is conveyed by the card convey unit in the discharging direction. The counting unit is enabled after a punching operation is performed by the punching unit, and counts the number of times of repetition of a reciprocal card convey operation in the opposite direction and the discharging direction. The control unit controls a convey operation of the card convey unit and repeatedly reciprocally conveys the card in the opposite direction and the discharging direction until the count value of the enabled counting unit reaches a predetermined count value. When the count value of the counting unit reaches the predetermined count value, the control unit conveys the card in the discharging direction and discharges the card.

Abstract: A Contact Smart Card (3) is inserted in a contact card reader and its capacitance is measured by applying a square wave generated by an oscillator (1) to it via a resistor (4). The capacitance effect of the smart card (3) affects the amplitude of the output from the resistor (1) and the output is monitored in an amplitude detector (2) connected to receive the signal output from the resistor (4) and to compare it against a threshold level for the signal previously established and stored for an acceptable card.

Abstract: The robust coding system makes use of a robust bar code on a label to enable a label reading system to automatically reconstruct label indicia information, even though the label has been damaged and is partially obliterated. An error correcting code is incorporated into the bar code sequence imprinted on the label to detect and correct a plurality of errors in the bar code. The error correcting bar code digits can be interleaved with the data imprinted in bar code form on the label or appended thereto. In addition, when the robust coding system is used on labels for data media cartridges, additional information is included in the bar code field to identify the type of media contained in the media cartridge.

Abstract: A bar code reader employs plural scanners for scanning a bar code mark with respective, plural optical scanning beams, counters connected with the scanners respectively producing numerical data representing the widths of corresponding black and white bars of the bar code. A composer selects the numerical data from the scanners so as to produce composed numerical data, and a decoder decodes the composed numerical data and produces a bar code data signal output. The composer, upon detecting a false data such as an overflow error data or waveform error data present in the respective numerical data output of a first selected scanner, switches therefrom to the respective numerical data output of a second scanner.

Abstract: An IC card comprises, a memory including a system area for storing system information, and a user area for storing user information, a CPU for controlling information read/write access of the memory, and a memory for storing program data for determining an operation of the CPU. The CPU stores predetermined data in the user area on the basis of a first command obtained from an external device, and compares the predetermined data with another predetermined data stored in the user area on the basis of a second command obtained from the external device. The CPU detects an abnormality of one of the memory, and data and address lines of the memory according to the result of comparison.

Abstract: A method and apparatus is disclosed for determining the remanent noise in a magnetic medium by DC saturation of a region thereof and measurement of the remaining DC magnetization. A conventional magnetic recording transducer may be used to determine the remanent noise. Upon determination, the remanent noise may then be digitized and recorded on the same magnetic medium to thereby "fingerprint" the magnetic medium. This "fingerprint" may then be later used to verify and authenticate the magnetic medium as being an original. In such manner, any magnetic medium, or any object having an associated magnetic medium, may be "fingerprinted" including credit cards, computer programs, compact discs, videotapes, cassette tapes, etc.

Abstract: Systems and methods for operating a data card terminal, such as a credit card transaction terminal, for providing chargeback protection services for the benefit of merchants are disclosed. The terminal includes a transaction terminal comprising an embossed character reader and magnetic stripe reader, with a separate signature capture printer. The transaction terminal is operative for detecting the physical presence of a data card during a card transaction. The embossed character reader employs a tactile imager and pattern recognition for detecting the embossed characters on the data card. A signature capturing printer prints a paper receipt, which is signed by a cardholder at a signature capturing window on the printer. A signature capturing system digitizes and compresses signals corresponding to the signature of the card holder.

Abstract: A system and method for monitoring barcode label quality at a point of sale which alerts an operator of a defective label and stores the number of defective labels for each manufacturer. The system includes an optical scanner, including a controller and a memory, a quality indicator, and a point-of-service terminal. The system may additionally include a central host computer. The method of the present invention puts the scanner in predetermined operating modes which activate the quality monitoring functions listed above.

Abstract: A method of entering a hand-marked response into a system by altering a predetermined modified bar code symbol in a manner so that the bar code is rendered readable. In this manner, bar code reading devices can be utilized to detect the hand-marked response. In an alternative embodiment, one of several potential responses may be marked and rendered non-decodable. A bar code reading device determines which of the several responses has been hand-marked by ascertaining which is non-decodable. Marking the response sheets may be aided by using an opaque template sheet or using a pressure sensitive overlay sheet.

Abstract: A data reading apparatus reads data of dots from a recording sheet on which data is recorded in the form of a mesh pattern, and decodes the read data into binary data. The data reading apparatus has an image sensor to read black/white levels of dots of the mesh pattern using the image sensor and to binarize the read levels by a hardware component or CPU processing according to software. An image can have a high recording density by minimizing a dot size.

Abstract: The present invention reads out track addresses written onto ID sections of a recording medium, for example, from five, tracks of the plurality of tracks read out simultaneously, to execute demodulation and error correction. In case where the addresses are multiple-written onto the ID sections, the optical spot judges the track address of the desired track on the basis of the plurality of read-out track addresses until the optical spot passes through the remaining track address. Further, in case where there is only a single one of the track addresses written on said ID sections, the track addresses are read out one by one, are demodulated and are error-corrected. The track address of the desired track is judged on the basis of the plurality of read-out track addresses, prior to the fact that the optical spot enters an information recording area.

Abstract: Coding systems utilizing machine-readable coding are disclosed. The coding systems are extremely simple to use and preferred embodiments of the machine-readable coding require no external reference or reference code or starting point or orientation for reading or decoding. The number of usable codes for any given number of code elements (bits or digits) is maximized, or, conversely, a minimum number of code elements is required for a given application, thus allowing each code element to be of maximum size for a given coding area. Also, methods and apparatus for encoding objects, and for reading, decoding, processing and using the information obtained from such encoded objects are disclosed. The coding may be applied to objects such as casino chips, currency, automated production line components, consumer products, household items, zip coded objects, etc.

Abstract: A method for reading bar code symbols which enables legitimate characters recognized by the code in use to be derived from a plurality of scans corresponding to illegitimate characters not recognized by the code in use is disclosed. The method includes the steps of storing representations of the bar code symbol which cannot be decoded to produce legitimate character(s). One of the representations is improved, or corrected, using another representation, and an attempt is made at decoding the corrected representation to produce a legitimate character. If the decoding attempt is not successful, further corrections are made in order to provide a representation which may be decoded to produce a legitimate character.

Abstract: An automatic transaction apparatus for dealing with cash or the like operates by being accessed by the user through the use of a user specific transaction medium card, which is inserted to the apparatus so that information recorded on it is read. In the event of some trouble of the apparatus, if the card cannot be ejected and returned to the user, a receipt slip of the card with information specific to the user being printed thereon is issued to the user in response to the ejection failure signal.

Abstract: The information recording method of the present invention comprises steps of recording information on a recording medium by a recording head during forward movement, reading the information recorded during the forward movement in the opposite sequence to the recording sequence during backward movement, and checking if the information has been correctly written or not based on the information read during the backward movement.

Abstract: A method and apparatus for testing bar code reader devices. A computer is programmed to receive data indicative of output signals of input devices for reading symbologies and to produce signals representative of those corresponding to the output of an input device. The computer then sends these representative signals to a subject bar code reader and receives the resulting signals produced by the reader. The computer also compares the received resulting signals with the representative signals to determine any differences. If the differences are judged to be significant, the computer produces an indicative signal.

Abstract: A portable, conveniently usable, and inexpensive non-contact bar code verifier permits testing of bar code labels at some arbitrary but constant distance from the verifier. Means are provided for analog analysis of bar code label contrast levels, and for derivation of new, instructive indices characterizing the readability and print quality. Additionally, a new method for determination of absolute bar code label dimensions is disclosed. The method of calibration for arbitrary scanning distance and angle standardizes not only the verifier's ability to measure absolute dimensions at unknown distances, but also its ability to discern contrast under arbitrary lighting conditions and scanning equipment. This is accomplished by employing calibration standards of known characteristics. Bar code verification information may be stored and/or employed for a variety of control and analytical functions as recognized in the art.

Abstract: An object verification system generates an incremental verification key which can be carried on the object co-extensive with the region of the associated randomly varying characteristic. The incremental key can be formed by measuring values of the characteristic and comparing selected pairs of values. The algebraic sign of the comparison can be used as an indicium for creating a verification key distributable across the region of the object. Alternately, the magnitude of the difference between the selected pairs of values can be also be included in some or all of the indicia.

Abstract: In a non-contact IC card, when the card is in a standby mode of operation a CPU provides a command to inhibit the application of a clock signal to digital circuitry including the CPU and/or to inhibit the application of an operating voltage to analog circuitry, except for an antenna circuit and a trigger signal demodulating circuit, so that power consumption in the standby mode is reduced. For transfer of data between the IC card and an external device, a trigger signal derived by demodulating received data in the trigger signal demodulating circuit is used to apply the clock signal to said digital circuitry and the operating voltage to all of the analog circuitry.

Abstract: An optical reader for reading high density dibit encoded data from a data strip comprises an optical detector (13) and a detector (14,15,DSP) connected to the optical detector (13) and arranged to decode its output. The detector includes a row of photosensitive elements arranged to extend transversely across a row of dibits and to form an image of the row of dibits. The decoder (14,15,DSP) includes a buffer (15) arranged to store the row image. An image transform device detects a skew angle of the strip and transforms the stored image to compensate for the distortion of the image.

Abstract: An indicia printing/verifying apparatus and an indicia scanning method are disclosed, in which a scanner is shifted in the line feed direction while indicia is scanned by the scanner so that even the indicia having a small length in the line feed direction can be completely scanned by the scanner without decreasing the printing/verifying speed of the apparatus.

Abstract: A method and apparatus for on-line evaluation of bar code symbol quality is disclosed in which bar code decoding and evaluation functions are integrated within a single unit. The integration of the bar code decoding and evaluation functions results in significantly more conclusive analysis of the quality of the bar code symbols as the analysis methodology and decoding process utilize a common scanning device. Thus, the ambiguities associated with hardware differernces between the decoding apparatus and stand alone bar code verifiers in evaluating the quality of the bar code symbols associated with conventional evaluation techniques are eliminated.

Abstract: A card carrier including pairs of rollers disposed at predetermined spacings along a card conveyer passageway such that the respective pairs of rollers hold both sides of a card therebetween. A driver including a single motor, a power transmission including a plurality of timing pulleys and a plurality of timing belts for transmitting the drive force of the motor to all the rollers, and power interrupting means including a clutch mechanism disposed between the power transmission and the motor for transmitting the drive force of the motor to the power transmission when the motor arrives at a predetermined rated rotational speed and a brake mechanism for stopping the operation of the power transmission instantaneously. When the motor arrives at the rated rotational speed, the clutch mechanism is actuated to drive all the rollers. When the card is to be stopped at a predetermined position, the drive force of all the rollers is stopped instantaneously by the clutch mechanism and the brake mechanism.

Abstract: An access control ticket having three fields of data, a first field of fixed data, a second field of variable data, and a third field of variable data is read and information processed by a microprocessor. The microprocessor determines the validity of information on the ticket data fields and which of the variable fields has older data. Writing only occurs on (over) the variable field with invalid or older data. Upon subsequent use, the ticket contains current access data (just written) and last previous access data, as well as fixed field data. This added data (past use) can be used for statistical analysis or other purposes. More importantly, the added data field reduces read/write reliability problems. One improperly written variable data field does not invalidate ticket, only the last variable data entry. The microprocessor is programmed to overwrite invalid data in one of the variable data fields during the next use.

Abstract: A bar code reading apparatus includes a bar code reader for generating, in a single operation, plural pieces of bar block data corresponding to a bar code having a number of digits which is a predetermined standard value, for example, 8 or 13. A detector detects the numbers of digits in each piece of bar block data generated by the bar code reader 11. A four digit memory and a six digit memory are used to store bar block data having four digits and six digits, respectively. A comparator detects whether or not the four digit memory and six digit memory each store bar block data. Each piece of bar block data output from the bar code reader 11 is stored in either the four digit memory or the six digit memory depending upon the number of digits detected by the digit detector. If the comparator determines that bar block data is stored in both the four digit memory and the six digit memory, then it is determined that the bar code reading operation is erroneous.

Abstract: A data transfer system for transmitting information from a portable device to at least one outside reading device, the portable device having first memory, the first memory storing the information which comprises a plurality of data blocks involving an error check data, the outside reading device reading the data blocks corrected by the error check data which is transmitted from the portable device.

Abstract: A method and apparatus for checking the correlation between all parts of a photofinishing order includes reading the identification numbers on at least some of the parts of the order using an optical character reader. The method includes processing the information received from the optical character reader to compensate for the inherent characteristics of optical character readers to misread portions of the numbers and includes a method of filtering misread and nonread information to prevent false alarm conditions in which an apparent mismatch is actually a misread, while minimizing the number of actual mismatches that are allowed through the system without causing an alarm. In one embodiment, a portion of the information is obtained in bar code form and a memory device is loaded with a table of bar code and optical character reader information for each order to maintain correlation between the order parts.

Abstract: In order to check if information stored on a card is authentic, the embossed character and figure information is compared with the information on the card. The rays radiated from the light emitting elements arranged in a line pass through a slit whose width is substantially equal to the thickness of embossed portions. Then, the rays are reflected on a card surface and received at an optical sensor consisting of LED elements arranged in a line as the card is in transit. The optical sensor is oriented in a manner to keep the same angle of reflection as the angle of incidence with respect to a normal. The light emitting elements are oriented to form another angle of incidence. These elements are used for reading the printed characters. To read a color pattern, a sensor having a photo detection sensitivity toward a normal of the card serves to receive the scattered rays reflected on the card, which rays are obliquely radiated to the card.

Abstract: An information-reading method employs an optical card including, a data section made by a linear information track, an address section for storing an address of the information track, and a guide section located adjacent to the address section and scanned before reading the address section. The address section and guide section are located at each end of said data section. The address and guide sections located at one end of the data section and the address and guide sections located at the other end of the data section are arranged in the same order in one scanning direction of the information track. The method comprises the steps of reading two addresses out of the address sections, by scanning the information track in the one scanning direction, and comparing the two addresses with each other, to thereby detect a tracking error.

Abstract: An image recording apparatus provided with a reader for reading information for identifying the original image; a recorder for recording the original on a recording medium; a transporting unit for transporting the original to the reader and the recorder unit; a detector for detecting the presence or absence of the identifying information on the original; and a controller for selecting whether or not to record the original according to the outputs of the detector and the reader.

Abstract: A portable electronic device comprising a clock generator for generating a clock signal, a power supply for generating a first power supply voltage, a low-voltage generator for generating a second power supply voltage lower than the first power supply voltage in response to the clock signal, an instruction circuit for instructing start of the clock generator, and a supply circuit for, when a start instruction of the clock generator is generated by the instruction circuit, supplying the first power supply voltage to the clock generator, and after the clock generator is started by the first power supply voltage, supplying the second power supply voltage to the clock generator.

Abstract: A signal processor digitizer circuit is disclosed for reading bar code symbols by detecting the times at which a scanning light spot moves from a space onto a bar code symbol or moved from a bar code signal onto a space. The novel signal processor digitizer circuit obtains all of its information for digitizing, false transition rejections, and margin cleaning from the first derivative of an analog signal produced by a photodetector detecting the scanning light spot. The original analog signal and a second derivative signal are not used which results in several advantages. Since the original analog signal is not needed, the signal differentiator circuit is placed at a very early stage in an amplifier string. Additional amplification stages can then be used to amplify the differentiated signal until it is large enough to be digitized. This results in two benefits.

Abstract: A data transmission arrangement for a portable data storage medium, in which messages are transmitted between an external device and a portable data storage medium at a plurality of times in response to one readout command output from the external device. When malfunction occurs during the processing in the portable data storage medium, the portable data storage medium outputs an abnormality response to the external device, and then receives a continuous data demand command from the external device. Thereafter, a status data different from the status data included in the first message is sent from the portable data storage medium to the external device. The external device recognizes this sent status data. Thereafter, the data transmission started in response to one readout command is not discontinued and additional data continuous to be transmitted.

Abstract: A toll paying system for use with a vehicle passing through a fast lane, having a toll booth. The toll paying system comprises detection means, class determining means, a wallboard, and a vehicle having both a first processor and a transmitter; a toll booth having antenna means, a receiver, a second processor, and camera means. The detection means may be embodied as a plurality of light beams traversing the fast lane with a plurality of light beam detectors. The light beam detectors generate a detection signal in response to a vehicle crossing the light beams. In general, the detection means generates a detection signal in response to detecting the presence of the vehicle in the fast lane. The class determining means may be embodied as an apparatus which determines the class of vehicle passing through the fast lane. The class of vehicle may be a car, truck, or any other type of class desirable for classifying vehicles passing through the toll paying system.

Abstract: A data card for a printer includes a plurality of data areas. Data readable by a sensor can be written in the data areas to control specifications or functions of a serial printer. A standard mark is printed on the data card to provide a reference position. The serial printer includes the data card, a card receiver into which the data card is detachably inserted, a sensor for reading data written in the data card, and a carriage having a printing head thereon. Either the card receiver or the sensor is mounted to the carriage. The other component is fixedly arranged within the serial printer. The serial printer further includes a memory for storing the data, and a controller for controlling a printing mechanism according to the data stored in the memory.

Abstract: A method of processing a signal in a bar code reader in which an optical signal provided by scanning a bar code is subjected to photo-electric conversion to provide an analog electrical signal, which is utilized to decode the bar code. The method includes scanning a bar code with a light beam whose diameter is small enough to detect thin bars and determining whether the bar code is a thin bar code or a thick bar code. If the bar code is the thick bar code, the reader employs data based upon analog electrical signals, whose frequency components higher than a first cut-off frequency determined for the thick bar code are cut off, as effective data. If the bar code is the thin bar code, the reader employs data based on analog electrical signals, whose frequency components higher than a second cut-off frequency determined for the thin bar code are cut off, as effective data.

Abstract: An image processing system specifies input image information on the basis of existence of a special mark or patterns printed on a job control sheet. Selected one of various image processings is executed in accordance with the existence of the special mark or patterns to thereby obtain output image information. Each of the special mark or patterns are line drawings, each drawn so as to have a certain low correlative angle to longitudinal and transverse directions of an image provided with the special mark or patterns.

Abstract: A portable bar code scanner includes a base member and a overhanging scanning housing secured to the base member. A laser power supply mounted in the housing outputs a laser beam along a first light path directed to a compact optical system in the housing which reflects the laser beam along a second light path which intersects the first light path at approximately ninety degress to scan a coded label positioned below the scaning housing. A collection lens mounted in the housing collects and directs the reflected light from the coded label to a detector which generates electrical signals for transmission over a cable to a processor.

Abstract: A card puncher for punching as a yardstick of use a card for getting coupon tickets on and used as tickets on omibuses and electric trains, and a method of controlling the card puncher. Data on a target quantity of conveyance of the card correponding to a position where the card is punched is stored in memory. A card conveyer is driven to convey the card by a quantity corresponding to data on the target quantity of conveyance stored in the memeory. A quantity of coast of the card after the drive of the card conveyer is teminated is measured. If the sum of the target quantity of conveyance and the measured quantity of coast of the card is within a predetermined allowable limit, the card is punched. If otherwise, data on the target quantity of conveyance in the memory is corrected such that the sum falls within the predetermined allowable limit, the card is returned to a position where the punching starts and the punching operation is retried.

Abstract: An electronic processor based system is provided which is capable of receiving plug-in cards. The plug-in card includes a memory which contains a first error check word which is a function of seed data words which are also stored in that memory. The first error check word is related to the seed data words by a predetermined algorithm. When the card is inserted in the processor system, the system reads the first error check word and the seed data words stored in the memory on the card. In one form, the processor system then performs its own independent calculation of a second error check word by using the same predetermined algorithm to operate on the seed data words retrieved from the card. The processor system compares the second error check word with the retrieved first error check word. If the second error check word is found to be the same as the retrieved first error check word, then the card is permitted to continue operation together with the system.

Abstract: A method for optically scanning a document having preprinted marking positions is disclosed. According to the invention, the document has a specified format including rows of preprinted marking positions to be scanned. Document size in at least one direction is automatically measured at each row of preprinted marking materials before that row is scanned. The scanning of each row of preprinted marking positions is automatically adjusted to compensate for random variations in shrinkage and expansion of document size. Document skew relative to the scanning camera is automatically measured at each row of preprinted marking positions to be scanned before scanning each row, and an indication that scanning should not continue is provided if any skew measurement exceeds a predetermined skew limit.

Abstract: Apparatus and methods of verifying objects utilize an inherent randomly varying and detectable characteristic of a recordable magnetic region affixed to the object. Detectability of the randomly varying magnetic characteristic can be enhanced by recording a selected electrical signal thereon. Digital and analog signals may be used. Both saturation and nonsaturation forms of recording can be used. A verification apparatus senses the enhanced randomly varying magnetic characteristic and compares it to a prestored representative profile previously created. Correspondence between the prestored profile and the currently read characteristic indicates an authentic object. Other objects can be rejected.

Abstract: A bit image converter for composing a decoder for converting the value of counting clocks loaded in response to the width of bars or spaces for composing a bar code into character information of a code reader is composed of a module number calculator for calculating the magnification of the basic module from the number of the modules for composing one code unit (one character), a module number total comparator for comparing the total sum of the number of the calculated modules with a specified number n of the modules, a module number corrector for correcting, if the number of the calculated modules is less than the specified number n (n-1), it to the specified number n, and a bit image output unit. Thus, the code reader is adapted for a multilevel bar code system so composed that a result becomes correct information by correcting, if the number of modules for composing one character is less than a specified number n, it.

Abstract: A machine readable binary code which is dynamically variable in size, format and density of information is provided. The binary code is formed as a matrix having a perimeter and data contained therein. The perimeter is provided with density indicia for indicating the density of data contained within the matrix. The perimeter is also provided with size indicia for indicating the size of the matrix. By utilizing the density indicia and size indicia, a scanning device is able to calculate the size and information density of the binary code.

Abstract: A system for reliably recording digital data on marginal magnetic recording medium by utilizing a two-track format and testing to locate pairs of record-quality areas of the medium. A magnetic stripe on a document is defined into a pair of recording tracks each with a sequence of bit locations. Associated pairs of bit locations (one from each track) are jointly tested for recording quality. One bit location of poor quality eliminates the pair; however, if both bit locations meet a standard, they are employed cooperatively to record data. Specifically, each bit location initially is recorded with a pulse. Any pair of bit locations which cannot meet the standard is totally cleared (erased), while pairs of bit locations meeting the standard are selectively erased to represent digital data.