Abstract:
An adapter for use with a conventional POS card reader to interface with PDA&#39;s, Wireless Phones, and other Handheld devices, through Infrared or RF media, such that signals received from, the devices can be, converted to conventional magnetic stripe and/or smart card format, as required by the conventional POS card readers. The adapter includes a housing, including at least a reader-insertable portion capable of being inserted in the card reader, a receive circuit in the housing, a processor in the housing connected to the receive circuit; and a point of sale interface in the reader insertable portion of the housing and connected to the processor. The housing may be approximately the size of a conventional credit card and may be fully reader-insertable. 
     The point of sale interface comprises a magnetic stripe emulator, a smart card emulator, or both. The magnetic stripe emulator may comprise at least one electromagnet. Two electromagnets may be used to emulate two tracks of a conventional magnetic card stripe. The receive circuit may comprise an infra-red receiver, a radio-frequency receiver, or other suitable circuit. The adapter may further include a transmit circuit, wherein the receive circuit and the transmit circuit include a transceiver. The adapter may further include a data buffer connected to the processor, the data buffer configured to purge data after a predetermined period of time or after a predetermined number of data transfer operations.

Description:
FIELD OF INVENTION 
     This invention relates generally to adapting an electronic transaction device to conventional point of sale terminals. In particular, the invention relates to an adapter that dynamically emulates a magnetic stripe of a conventional plastic card, metallic contacts of a smart card, or both. 
     BACKGROUND 
     The subscriber base for wireless telephones is already enormously large and is forecast to grow rapidly. Some estimates put current wireless telephone subscribers at 400 million users globally, and telephone manufacturers estimate that one billion wireless telephones will be in use by 2004. Wireless telephones typically have a compact housing with microprocessor, memory, input and output circuits and a battery. Wireless telephones also include dialing, transmitting and receiving circuitry. There are various embodiments of wireless telephones, including analog (AMPS), Global Standard for Mobile Communication (GSM), code division multiple access (CDMA) and time division multiple access (TDMA). In addition to basic communications circuitry, wireless telephone manufacturers are adding features normally found on electronic organizers, such as date books, address books, and infra-red communications devices. 
     Personal Digital Assistants (PDAs) are also becoming very popular. PDAs are a form of handheld electronic organizer, typically having date books, address books, to-do lists, memo pads, and other features. PDAs typically include a compact housing with a hardware environment consisting of a microprocessor, memory, input and output circuits and a battery. Many PDAs include metallic contacts and infra-red circuitry for input and output circuitry. Various operating systems are available, as are various software applications. Operating systems for PDAs include Palm OS, Windows CE, and other operating systems. Some PDAs are integrating wireless communications. 
     Another type of handheld electronic device is a Universal Electronic Transaction Card (“UET Card”). UET Cards have been proposed to receive, store, and process information relating to a plurality of different accounts, thereby consolidating numerous cards into one card. See, for example, U.S. Pat. Nos. 5,590,038 and 5,884,271, the disclosures of which are incorporated by reference. In one example of a Universal Electronic Transaction Card, the card stores electronic images of the plastic cards which it replaces, and allows a user to conduct a transaction at a Point of Sale Terminal (POS). 
     It is contemplated that these handheld devices will become integrated to one degree or another. For example, UET Cards have been proposed with many features of currently available PDAs. See, for example, the previously mentioned U.S. Pat. Nos. 5,590,038 and 5,884,271. Also, as mentioned above, some wireless telephones are integrating PDA type functions, and some PDAs are integrating wireless communications. Additionally, PDAs, wireless telephones and other handheld computing devices may be programmed or otherwise configured and used to conduct electronic transactions. UET Cards, and computing devices programmed to perform electronic transactions, such as PDAs and wireless telephones, are generally referred to herein as “electronic transaction devices.” 
     Generally, an electronic transaction device may be a handheld device configured to allow a user to electronically emulate some or all of various aspects of a traditional wallet containing an assortment of plastic cards, cash and cash equivalents. One of the advantages of an electronic transaction device is the fact that the device allows the storage and use of multiple plastic cards—multiple credit and debit cards, identification cards, multiple membership and affinity group cards etc. Existing credit card (and other plastic card) images may be electronically stored and reproduced on the electronic transaction device display. Receipts may also be stored, eliminating paper receipts. Electronic transaction devices may include additional features, such as wireless telephony and PDA features. 
     Another large installed base of equipment comprises Point of Sales (POS) terminals. POS terminals include terminals having plastic card magnetic stripe readers and terminals having smart card readers. 
     Plastic cards having a magnetic stripe are known to be used with POS terminals having magnetic stripe readers. Relevant industry standards for magnetic stripe cards include, but are not necessarily limited to, ISO 7810, ISO 7811, and ISO 7813. Some examples are plastic Credit Cards, Bank—Debit &amp; Check Cards, Automatic Teller Machine Cards, Membership Cards, Business or Access Cards, Identification Cards, College Identification Cards, Airline Cards, and others. The magnetic stripe generally includes pre-recorded information, which may identify the card issuer, account number, identity of an authorized card user, or other relevant information. Typically, the magnetic stripe is used to establish the identity of the cardholder or enable a transaction. Such transactions may or may not be monetary in nature. 
     Another type of card is a “smart card.” Smart cards are available with metallic contacts, without metallic contacts, and as hybrid cards. The standard for contact-type smart cards is ISO 7816. Contactless-type smart cards will be governed by the ISO 14443 standard. “Smart cards,” as used herein, refers to cards adhering to one or both of these standards. 
     A typical POS may include a card reader, such as a card reader configured to read magnetic stripes conforming to ISO 7810, ISO 7811, and ISO 7813. By “swiping” a magnetic stripe card through the card reader, the card reader establishes the account number and identity of the cardholder. Such a POS reader may then communicate with the issuer of the card to determine the validity of the account and consequently approve or deny the transaction. 
     POS card readers are not limited to sales transactions. In offices, manufacturing facilities, or business environments, for example, employers may issue plastic identification cards to employees with a magnetic stripe on the card. This enables the readers to establish the identity of the cardholder, unlock doors or gates, log in and log out the entry and exit times respectively and in certain cases compute wages. In a school, college or university, an identification card with the magnetic stripe allows students to access laboratories, libraries, and other campus facilities, store cash values for transactions on campus. In these situations, the magnetic stripe on the plastic card is an important component which enables the card to function in the targeted environment. 
     With an electronic transaction device, one possible way of using it at a POS for performing a transaction (depending on the environment in which the device is being used, the transaction may or may not be monetary in nature) is to transmit information through an infrared or proximity RF link or by wireless or wired telephone link. PDA&#39;s, wireless telephones, and UET Cards may be equipped with an infrared transceiver. Wireless telephones of course, include wireless telephone communications circuitry. However, sending information to and receiving information from a POS or terminal equipment (TE) would require the POS (or TE) to also be equipped with a corresponding transceiver, along with the supporting hardware, software and training for the personnel handling the equipment. 
     Currently existing POS terminals comprise an extensive infrastructure of card readers, both magnetic and smart card, and the supporting networks and protocols for communication. One potential hurdle for the widespread adoption of electronic transaction devices such as Universal Electronic Transaction Cards and similarly configured PDA&#39;s and wireless telephones is compatibility with the existing infrastructure of magnetic card readers. For example, the prospect of including a pre-recorded magnetic stripe dedicated to one account on an electronic transaction device may impair one of the benefits of the electronic transaction device, namely, the ability to conduct transactions using a plurality of accounts. Also, retrofitting the established pre-existing base of POS terminals with a new communication port such as infra-red or radio frequency communication, would require both hardware and software modifications. Also, the introduction of such modifications may necessitate re-training of personnel that operate POS terminals. The cost of such modification is not trivial, considering the number and variety of POS terminals, such as grocery store registers, automatic teller machines, and pay-at-the-pump filling stations, to name a few. 
     SUMMARY 
     What is provided is an adapter for use with a conventional POS card reader to interface with PDA&#39;s, Wireless Phones, and other Handheld devices, through Infrared or RF media, such that signals received from the devices can be converted to conventional magnetic stripe and/or smart card format, as required by the conventional POS card readers. The adapter includes a housing, including at least a reader-insertable portion capable of being inserted in the card reader, a receive circuit in the housing, a processor in the housing connected to the receive circuit; and a point of sale interface in the reader insertable portion of the housing and connected to the processor. The housing may be approximately the size of a conventional credit card and may be fully reader-insertable. 
     The point of sale interface comprises a magnetic stripe emulator, a smart card emulator, or both. The magnetic stripe emulator may comprise at least one electromagnet. Two electromagnets may be used to emulate two tracks of a conventional magnetic card stripe. The receive circuit may comprise an infra-red receiver, a radio-frequency receiver, or other suitable circuit. The adapter may further include a transmit circuit, wherein the receive circuit and the transmit circuit include a transceiver. The adapter may further include a data buffer connected to the processor, the data buffer configured to purge data after a predetermined period of time or after a predetermined number of data transfer operations. 
     A method of using an adapter of the present invention with a point of sale card reader may include the steps of selecting a card on an electronic transaction device, placing the adapter in the card reader, transmitting information corresponding to the selected card from the electronic transaction device to the adapter, the adapter converting the information corresponding to the selected card to a format readable by the card reader, and the card reader reading the converted information. 
     The step of converting the information corresponding to the selected card to a format readable by the card reader may further comprise emulating a magnetic stripe or emulating a smart card. The step of emulating a magnetic stripe may further comprise generating electromagnetic signals. The step of emulating a magnetic stripe may also further comprise receiving the information corresponding to the selected card, formatting the information corresponding to the selected card to conform with magnetic stripe conventions, and dynamically writing the formatted information to an electromagnet. 
     The step of placing the adapter in the card reader may occur before the step of transmitting information. Alternatively, the step of transmitting information may occur before placing the adapter in the card reader, and further comprises the step of buffering the information corresponding to the selected card in the adapter. The buffered information may be purged after the step of reading the buffered information at the card reader. 
     In another embodiment, an electronic transaction device is adapted for use with point of sale card readers, and includes a housing, adapted to fit in a pocket or purse, the housing including at least a reader-insertable portion capable of being inserted in the card reader, a processor, enclosed in the housing, adapted to process account information relating to at least one service institution account associated with a user of the electronic transaction device, a display, connected to the processor and adapted to display the account information, a memory, connected to the processor and adapted to store the account information; and a point of sale interface in the reader insertable portion of the housing, connected to the processor and adapted to transmit the account information to a point of sale card reader. The point of sale interface may comprise a magnetic stripe emulator, a smart card emulator, or both. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is an illustration of one example of an adapter of the present invention. 
     FIG. 2 is an illustration of one example of an adapter of the present invention in combination with a conventional magnetic stripe card reader. 
     FIG. 3 is an illustration of an electronic transaction device in conjunction with an example of the adapter card of the present invention. 
     FIG. 4 is an illustration of a conventional plastic card with a magnetic stripe. 
     FIG. 5 is an illustration of a conventional plastic card with a magnetic stripe and a conventional magnetic stripe card reader. 
     FIG. 6 is an illustration of an example of an electronic magnetic coil of one example of the present invention. 
     FIG. 7 is an illustration of an example of an adapter of the present invention having a magnetic stripe POS interface. 
     FIG. 8 is another illustration of the example of the adapter card having a magnetic stripe POS interface. 
     FIG. 9 is an illustration of another example of an adapter of the present invention having a smart card POS interface. 
     FIG. 10 is another illustration of the example of an adapter card having a smart card POS interface. 
     FIG. 11 is an illustration of another example of an adapter of the present invention having a smart card POS interface and a magnetic stripe POS interface. 
     FIG. 12 is an illustration of another example of an adapter card of the present invention. 
     FIG. 13 is a flow chart of a method of use of the present invention. 
     FIG. 14 is an illustration of an electronic transaction device including another example of the present invention. 
     FIG. 15 is a block diagram of an electronic transaction device including another example of the present invention. 
    
    
     DETAILED DESCRIPTION 
     Referring to FIGS. 1 and 7, one embodiment of an adapter  10  for electronic transaction devices is illustrated. A housing  12  encloses a receive circuit  14 , a processor  16 , a battery  18 , and a POS interface circuit  20 . The POS interface circuit  20  may comprise a magnetic stripe interface  20   a , a smart card interface  20   b , a combination of a magnetic stripe and a smart card interfaces, or other suitable POS interfaces. 
     The housing  12  may have external dimensions approximately the same as conventional plastic cards with magnetic stripes. See FIGS. 2,  8 , and  10 . In the alternative, referring to FIGS. 7,  9 , and  12 , the housing  12  may be thicker, or otherwise larger or smaller than, a conventional plastic card, and further include a portion  36  that may be inserted into a conventional card reader  44 . 
     The receive circuit  14  may comprise an infra-red receive circuit, a proximity radio-frequency circuit, a wireless application protocol (WAP) circuit, a metallic contact circuit, or other suitable circuit, or any combination thereof. Alternatively, receive circuit  14  may further comprise a transmit circuit  22 , and thereby comprise a transceiver  24 . The processor  16  takes the data received by the receive circuit  14  and processes the data into a format compatible with a conventional card reader  44 . 
     The processor  16  may be configured to have identification information, such as a unique identification number or other information. For example, if used in a retail store environment, the processor may be configured with the retail store name, location, and department within the store. The processor may also be configured with a unique identification number. In another example, if privately used by the user of an electronic transaction device, the processor may be configured with the name, address, and telephone number of the user. This information may be programmed by the card manufacturer, issuer, or user. 
     Referring to FIGS. 2 and 3, in use, the adapter  10  is placed in the card reader  44  with the POS interface circuit  20  positioned near the sensors of the card reader  44 . The adapter  10  may be held stationary during a read operation. An electronic transaction device  60  transmits the information via I/O interface  68  that would typically be pre-recorded on a magnetic stripe  42  or smart card chip to the adapter  10 . The adapter  10  receives the information, formats the information to conform with conventional card reader formats, and writes data to the POS interface  20 . In the case of magnetic stripe emulation, reliability may increase because the rate of the data being transmitted from the adapter  10  to the card reader  44  is now controlled by the hardware and software of the electronic transaction device and adapter  10 , rather than by a “swipe” of a card through a card reader  44 . 
     The conventional hardware and software of card readers  44  do not require change. In the example of an adapter  10  with the electromagnets  30  simulating a magnetic stripe  42 , data is dynamically written to the POS interface circuit  20  to emulate a conventional card swipe. Accordingly, the adapter card neither has “static” nor “spatially coded” data. The processor  16  and POS interface circuit  20  convert digital data into an alternating current signal through the electromagnets  30 , which induce flux changes in the reading sensor. The flux changes correspond to the motion of a static pattern of magnetic bits past a sensor. The magnitude of the flux change induced by the coil is within defined standards for conventional magnetic stripe cards. 
     The POS interface  20  may be designed to dynamically emulate a conventional static magnetic stripe  42  on a conventional plastic card  40 . In the context of emulating a conventional plastic credit card, such emulation may include conforming signal strength and data formats to relevant industry standards, such as ISO 7810, 7811, and 7813. Referring to FIG. 4, such a conventional typical plastic card  40  including a magnetic stripe  42  is illustrated. The thickness of such a card is about ˜0.75 mm. The dimensions of the actual stripe may differ from one card manufacturer to another, but each stripe typically has information magnetically encoded in the form of two to three tracks. These tracks contain data magnetized on the stripe  42 . The data is generally pre-recorded by the card issuer and is not configurable by the card user. In the context of cards other than conventional plastic credit cards, emulating a magnetic stripe may involve different relevant standards. 
     Referring to FIG. 5, a cut out front view of a conventional magnetic card reader  44  is illustrated. The card reader  44  may be connected to a cash register and a bar code reader at the POS of a merchant, or may be connected to some other terminal equipment in a non-retail environment. FIG. 5 also shows a plastic card  40 , with the information on the magnetic stripe  42 , being “swiped” through the card reader  44 . The pre-recorded data on the conventional plastic card  40  may be thought of as static, spatially coded data. The data is “static” because it typically does not change value over time. The data is “spatially coded” because the magnetic information is in sequence from one end of the stripe to the other, and does not change location. 
     FIG. 5 shows an arrow along the length of the stripe, which indicates the direction in which the card is being swiped. The 1&#39;s and 0&#39;s on the arrow are symbolic of the digital data magnetized on the stripe. This static data on the card is stored using frequency encoding. Another arrow, leaving the reader, depicts the information being read off the card and being sent over a network, typically for validation to the card issuer. 
     In this example, the pre-recorded “0” encoded spatially first on the magnetic stripe  42  is read chronologically first by the magnetic card reader  44 . The plastic card  40  is swiped quickly through on a groove provided to guide the plastic card  40  through the card reader  44 , enabling sensors on the card reader  44  to read the spatial information magnetized on the tracks. The swiping motion of the spatially-encoded data of the plastic card  40  past the stationary sensors of the card reader  44  effects a transmission of the spatially encoded data in time. The rate of transmission is determined by the speed at which the plastic card  40  is swiped. Since the rate of “swipe” is often controlled by a person, card readers  14  are designed with broad tolerances. The typically induced signal strength when a plastic card  40  with a magnetic stripe  42  is swiped in a card reader  44  is ˜20 mV. 
     Referring to FIGS. 6,  7 , and  8 , one example of a POS interface circuit  20   a  comprising a magnetic field circuit is illustrated. The illustrated example is an electromagnet  30  having a core lamination  32  wrapped with a wire coil  34 . A laminate of ˜0.5 mm thickness may be used, with a total assembly thickness at ˜0.75 mm, thus maintaining the same overall thickness as conventional plastic cards. The wire coil  34  may comprise  42  gauge copper wire. 
     Referring to the example illustrated in FIG. 8, there are two electromagnets  30 , positioned on the housing  12 , so that when the adapter  10  is placed in a card reader  44 , the electromagnets  30  are aligned with the sensors on the magnetic card reader  44 . If the housing  12  is of an embodiment with only a portion that may be inserted in the card reader, the electromagnets  30  of the POS interface circuit  20   a  are substantially located in the insertable portion. The electromagnets  30  are embedded in the housing in the approximate position of one or more tracks of a magnetic stripe. In the illustrated example, two electromagnets  30  are illustrated, each coil emulating one track of a pre-recorded magnetic stripe. However, one electromagnet  30  may be used to emulate a single track, or three or more electromagnets  30  may be used to emulate three or more tracks. In the given example of electromagnets  30 , the inductance of one coil was recorded as ˜1 mH, and with a current of 10 mA at 4 kHz a signal strength of 25 mV was generated in the card reader. 
     The method of dynamically writing data to a set of coils may also be achieved under a different set of physical parameters for the electromagnets  30 . Also, devices for producing a dynamically changeable magnetic field other than electromagnets  30  may be used without departing from the scope of the invention. 
     Referring to FIGS. 9 and 10, an alternative embodiment of POS interface circuit  20   b  comprising a smart card interface  50  having metallic contacts  52  is illustrated. “Smart cards” are known plastic cards having electronic storage of information in lieu of, or in addition to, a magnetic stripe. Smart card readers read information from “Chip on Plastic” by physical (metallic) contact with the IC on the Smart Card. According to ISO 7816, eight contacts are provided on a smart card; I/O (serial date input and output); Vpp (programming voltage input); GND (ground reference voltage); CLK (clock signal); RST (reset); Vcc (power supply); and two contacts reserved for future use. ISO 7816 also provides for contact size, position, electrical signal descriptions, and operating procedure. Emulation of a smart card interface generally involves providing contacts and formatting data in adherence with relevant industry standards, such as, but not limited to, ISO 7816. There may be additional standards to emulate, such as ISO 14443, and other types of smart cards other than credit cards having their own standards. 
     Referring to FIG. 11, another alternative embodiment of the adapter  10  is illustrated. In this embodiment, both POS interface  20   a  comprising electromagnets  30  and POS interface  20   b  comprising a smart card interface  50  are incorporated on a single adapter  10 . Additionally, a metallic interface for communicating with devices or networks other than POS terminals may be included. For example, interfaces for wired or wireless telephone circuits may be provided, as may be interfaces for LAN computer networks. 
     In an alternative embodiment, illustrated in FIG. 12, housing  12  is not necessarily the same size as a conventional credit card. In the illustrated example, the adapter  10  may be thicker than a conventional credit card in some places, to accommodate circuitry or batteries or the like. The adapter  10  may further comprise a housing  12   a  having a portion  36  that is insertable in a card reader  44 . The POS interface  20 , electromagnets  30 , for example, may be located in the reader insertable portion  36 . In another example, the adapter  10  may be configured as a lid or cover for an electronic transaction device, wired into the electronic transaction device, the cover being flipped open for use. 
     Referring to FIG. 13, in use, in step  80 , a user selects a card to be transmitted to the adapter. In step  82 , the adapter  10  is placed in the card reader  44  with the POS interface circuit  20  positioned near the sensors of the card reader  44 . Rather than recording predetermined data spatially on a card, and requiring a “swipe,” the adapter  10  may be held stationary during a read operation. In step  84 , an electronic transaction device  60  transmits the information via I/O interface  68  that would typically be pre-recorded on a magnetic stripe  42  to the adapter  10  by infra-red circuitry, proximity radio frequency circuitry, or other suitable wired or wireless communication means. In step  86 , the adapter  10  receives the information via receive circuit  14  (alternatively, transceiver  24 ), formats the information to conform with conventional card reader formats, and dynamically writes-data to the POS interface  20  (in the illustrated example, electromagnets  30 ) thereby emulating a swipe of a conventionally pre-recorded magnetic stripe  42 . 
     The adapter  10  writes the data at a rate and format in which card readers  44  are designed to read the data. In one illustrated example, a processor  16  dynamically writes data to the POS interface circuit  20 . The electromagnets  30  of the POS interface circuit  20  on being energized by the battery, generate a magnetic field. The processor  16  is supported by digital to analog converters and software routines and dynamically writes data to the POS interface circuit  20 . The magnetic fields generated by the POS interface circuit  20  are sensed by the card reader  44 . Because the adapter  10  is not “swiped,” data is dynamically written to the POS interface circuit  20  emulate a conventional card swipe. The processor  16  and POS interface circuit  20  converts digital data into an alternating current signal through the electromagnets  30 , which induce flux changes in the reading sensor. 
     In the alternative embodiment including a POS interface circuit  20   a  comprising a smart card interface  50 , the method of use is similar. The electronic transaction device  60  transmits information to the adapter  10 , which processes the information and emulates a conventional smart card via contacts  52 . 
     In steps  88  and  90 , the card reader  44  sends the data necessary for authorization of the transaction and acts upon the response. If authorization is denied in step  90 , the transaction is rejected in step  92 . 
     A check is made in step  94  as to whether bi-directional data flow is possible through the card reader  44 . Return communication of information from the adapter  10  to the electronic transaction device is optional. For example, the POS terminal may not be configured to return an electronic receipt to the electronic transaction device through the adapter. In such an example, a conventional paper receipt may be generated and signed in steps  96  and  98 . Additionally, the adapter  10  may return confirmation information regardless of whether the card reader  44  is capable of bi-directional data, including an indication that the account information was received and processed by the adapter. Conformation information may also include identification information of the adapter  10 , such as retail store location, department, the date of purchase, and a unique identification number. 
     It is contemplated that POS terminals may be equipped to transmit transactional information to the adapter, such as an electronic receipt. In this case, the POS may generate a paper receipt in step  100  and transmit the transactional information, including, for example, an electronic receipt, to the electronic transaction device  60  via the adapter  10 , in step  102 . The receipt may be signed in step  104 . 
     It is contemplated that the user of an electronic transaction device  60  may not want to hand an electronic transaction device to a merchant. For example, in a restaurant, credit card transactions are often accomplished by handing a conventional plastic credit card to a member of the waitstaff who, in turn, takes the card to a card reader, swipes the card through the card reader, and returns the card to the user. Due to the extensive amount of information included on an electronic transaction device  60 , however, users may be reluctant to hand such a device to the waitstaff. 
     According to another example of the present invention, therefore, the adapter  10  may temporarily buffer information from an electronic transaction device to subsequently conduct a transaction outside the range of the electronic transaction device&#39;s infra-red or radio frequency capabilities. Continuing with the restaurant scenario, the waitstaff presents the adapter  10  and the user transmits relevant information from the user&#39;s electronic transaction device  60  to the adapter  10 . The adapter  10  stores the information in a buffer, such as memory, registers, or other suitable storage means, until the waitstaff has an opportunity to run the adapter  10  through the card reader  44 . After being read, the buffer is purged. The data buffer may be purged after a predetermined period of time or after a predetermined number of data transfers. 
     Optionally, the adapter  10  may be configured to buffer information from more than one electronic transaction device  60 . Such a configuration would facilitate persons sharing the expenses of a transaction, such as when splitting the bill at a restaurant. Also, such a configuration would facilitate collecting payment information corresponding to more than one transaction. 
     In an alternative embodiment, the adapter  10  can receive information from the card reader  44  and transmit the information back to the electronic transaction device. In this embodiment, the receive circuit  14  further comprises a transmit circuit  22 . Continuing with the restaurant scenario, the POS terminal transfers details of the transaction to the adapter  10 . The waitstaff returns the adapter  10  to the proximity of the electronic transaction device  60 , and transfers the details of the transaction to the electronic transaction device  60 . 
     The present invention is not limited to stand-alone adapters. In another alternative embodiment, illustrated in FIGS. 14 and 15, an electronic transaction device  60  includes an extension  62  that includes the POS interface circuit  20 . The electronic transaction device  60  may comprise a microprocessor  64 , coupled with memory  66  adapted to store an operating system, BIOS, applications and user data, I/O interfaces  68 , display  70 , and battery  72 . One example of interacting with an electronic transaction device  60  is when display  70  further comprises a touch sensitive liquid crystal display. Other modes of interacting include keypads (in the example of a wireless telephone), pointing devices and conventional reduced-size “QWERTY” keyboards. Typical input and output interfaces that may comprise I/O interface  68  may comprise infrared devices, including those adhering to IrDA standards, proximity radio frequency devices, such as the “Bluetooth” standard, metallic contacts, such as the RS-232 standard, or bar codes. 
     The data flow to the POS interface  20  is controlled by the microprocessor  64  and other supporting hardware and software of the electronic transaction device  60 . The extension  62  may be part of a housing for the electronic transaction device  60 , or a separate add-on module or circuit board. For example the extension  62  may plug into an expansion slot on an electronic transaction device  60 , or comprise a lid or cover for the electronic transaction device  60  that may be flipped open for use. In another example, illustrated in FIG. 15, the extension  62  is clipped on to the serial port of an electronic transaction device  60 .