Abstract: Air jets are used to entrain ambient air for forced air cooling of electronic components. In the preferred embodiment, individual air jets are associated with each circuit card to entrain and induce flow of a much greater volume of ambient air over each card, thereby cooling it. Modularization and "hot" servicing are facilitated because each circuit card may have its own cooling system, all of which may be powered by a central source of compressed air. The compressed air source may be remotely located resulting in lower noise and more compactness.

Abstract: An electronic funds transfer system wherein it is required that a bank be reasonably guaranteed that the two parties to a retail transaction (i.e., a person and a retailer) agree on the transaction before the funds transfer takes place. The message including the transaction information is encrypted by the person using a unique encryption key (K.sub.P) stored in a highly secure storage location in his own personal portable transaction device (XATR) and his data storage and transfer card (DSTC) and this first encrypted message is sent to the retailer who doubly encrypts the initially received encrypted message from P under his own unique encryption key (K.sub.R) and this doubly encrypted message is sent to the bank. The person also sends the transaction message to the retailer in clear, and the retailer first verifies the message and then, utilizing his own encryption key (K.sub.R), encrypts same and similarly sends it to the bank.

Abstract: A method and apparatus for identifying an individual holder (person) of an unalterable charge card-like device (CARD) at a utilization terminal (U/I Terminal) wherein a unique user entered key (asserted key K.sub.A) is handled in a highly secure manner. The holder of the CARD causes same to be placed in a data coupling mode with the U/I Terminal. At this point, the person enters asserted key (K.sub.A) via a keyboard associated with said system. A random word is generated by at least one random word generator located in said CARD and this random word is encrypted utilizing the asserted key K.sub.A entered by the holder at the keyboard and also encrypted under a true key K.sub.T stored in said CARD. The random word encrypted under the asserted key K.sub.A is stored in said U/I Terminal and the random word encrypted under the true key K.sub.T is stored in the CARD.

Abstract: A personal portable terminal for financial transactions adapted for use with one or more data storage and transfer cards (DSTCs) and other external devices, such as point of sale terminals, is disclosed. The transaction device includes keyboard means for entering transaction data and control information, means for temporarily storing transaction data, and logic means for performing arithmetic, logical, and control operations. Said logic means further includes means for storing predetermined programs which are activated by instructions entered via said keyboard. Also included are display means for selectively displaying transaction data and means for transferring selected data from the transaction device into suitable storage means located in said other external device and into at least one DSTC. Further means are disclosed whereby account balance data in one DSTC may be credited while account balance data in another DSTC is debited as a result of the transaction.

Abstract: A Minimum Delay Module Assembly, having unrestricted accessibility for servicing, that provides substantially constant electrical and thermal environments for all portions of the assembly regardless of configuration. The assembly comprises a plurality of vertical page modules in which each page module is vertically hinged to the adjacent page module. Electrical interconnections are provided between the page modules by means of cable assemblies which enter each page module in the edge thereof adjacent said hinges. Individual self contained cooling means are provided for each page module so that the flow of air is up through the bottom of each page module and out through the top thereof. Resilient conduit means may be utilized to supply a pressurized coolant to each page module regardless of the configuration of the module assembly.

Abstract: Exposure images may be synthesized on a radiation responsive surface by causing effective relative motion between a mask and the surface. The mask contains at least two distinct exposure areas, each having a plurality of apertures arranged in different patterns from which at least two different images can be simultaneously synthesized. Radiation is directed through the plurality of apertures in a mask during a given period to expose a plurality of similarly shaped areas on a surface. During a second period electrons are similarly directed through the same mask which has been effectively displaced and a second plurality of contiguous areas are exposed. During third and fourth succeeding periods, third and fourth pluralities of contiguous areas are exposed. Thus, the image in each exposure area is synthesized from a plurality of contiguous four step exposure images which makes it possible to eliminate the "stencil problem" and permit exposure of areas whose length is very much greater than their width.

Abstract: The broad band directional signal generator disclosed generates signals on a transmission line, which, controllably propagate in one direction on the line to the exclusion of the other direction, or in both directions. Such signal generation may occur at one or a multiplicity of points located at arbitrary positions along the line. The signal generator includes a conventional .pi., 0, T, or H attenuator network and operates in conjunction with other circuitry. In the disclosed embodiments, symmetrical attenuators are used with either single ended or push-pull amplifiers connected to the attenuator nodes. The invention, however, is equally applicable to .pi., 0, T, or H attenuator networks which are not symmetrical. The specific embodiments shown employing active devices and direct coupling have wide frequency responses which are flat and flat to DC. Where operation down to DC is not required, AC or transformer coupling may be used.

Abstract: A broad band directional coupler including a conventional attenuator is disclosed. The coupler permits detection of signals propagating simultaneously in opposite directions on a single-signal path or transmission line. Detection may occur at one or a multiplicity of ports located at arbitrary positions along the line. In the specific embodiments disclosed, the attenuators employed are symmetrical, .pi., O, T, and H attenuator networks. The invention, however, is equally applicable to .pi., O, T or H attenuator networks which are not symmetrical. The specific embodiments shown employing active devices have wide frequency responses which are flat and flat to DC. Where operation down to DC is not required and where a broad band directional coupler comprised entirely of passive elements is desired, a version of the coupler circuit employing transformers is disclosed.