Abstract: A keyboard, in particular a POS (point of sale, point of service) keyboard, bank keyboard, keyboard for secure data entry, and a method for secure transmission of data that is entered through various data entry modules such as, e.g., magnetic card readers, chip card readers, key switches, or a keypad, to an external device connected to the keyboard, for example a computer. The keyboard comprises at least one data entry module for entering data and a keyboard control device with at least one receiving device for receiving the entered data, an encryption device for encrypting the received data by means of an encryption algorithm, wherein the encryption algorithm is present in the form of program code, and a transmission device for transmitting the data encrypted by the encryption means to the external device connected to the keyboard control device, wherein the encryption algorithm can be selected by the user from multiple predefined encryption algorithms and associated with the data entry module.

Abstract: A keypad, particularly a point of sale keypad, is disclosed that includes a key block, a microprocessor, at least one read-only memory, in which the firmware required for operating the keypad is stored, and at least one interface for connecting the keypad to an external device. Further, a method is disclosed for starting up the keypad and for replacing or updating the keypad firmware. So that it is usually not necessary to open the keypad to replace or update the firmware, the invention proposes providing at least one programmable read-only memory in the keypad, in which a boot program and the firmware are stored in separate memory areas, and in such a way that the first memory area containing the boot program cannot be erased during normal operation of the keypad.

Abstract: A method is disclosed for entering and/or changing the data assigned to keys and/or accessory devices of a freely programmable keyboard and stored in at least one programmable memory, a method for retrieving these data, and to a keyboard for carrying out the method. So that despite limited available memory space in the freely programmable memory, the particular keyboard can be optimally adapted to user requirements, the invention proposes dynamic management of the programmable memory of the keyboard, i.e., only as much memory space is used per key as is actually necessary for this. The unneeded memory space is therefore available to the other keys.

Abstract: A method, and data switching center, for reserving transmission capacities and for selecting requests for data streams of different bandwidth to be transmitted in digital data transmission networks. The method and the data switching center are characterized by the fact that a request for transmitting data having a certain bandwidth is accepted only if the unused data transmission capacity is greater than or equal to the sum of the reserved data transmission rates, with the exception of the reserved data transmission rate for the requesting bandwidth or bandwidth group, even after the transmission has been accepted.