摘要:
While executing program code arranged in nested blocks, a data processing system accumulates words in a stack storage means comprising a pair of registers coupled to an arithmetic unit and supplying thereto operands for processing; a plurality of memory locations in a relatively large-capacity, low-speed memory; and a relatively small-capacity, high-speed memory having a plurality of addressable extension locations. Register means are set to associate the extension locations in one-to-one correspondence with a group of memory locations so as to define corresponding pairs of locations. Each pair is reserved for storing a different stack word and has four occupancy conditions. Before the actual accumulation of the stack word for which the pair is reserved, the pair is in a first condition wherein both locations of the pair are unoccupied. After actual accumulation, the pair is either in a second condition wherein only the extension is occupied, or in a third condition wherein only the memory location is occupied, or in a fourth condition wherein both locations are occupied. Preferably each extension location has occupied and copy indicating storage cells having four states each indicating one of the four possible conditions. Stack words forming the record of execution of a first program block are initially accumulated in the extension locations. When a second program block nested within the first program block is entered the record of execution of the first block is transferred to the presently corresponding memory locations and then the associating register means is set to associate the extension registers with a different group of memory locations so that the extension locations are available to store stack words for the second block. The stack includes a linked list of control words containing stack depth information indicating the number of stack words accumulated in executing each block. Upon a transfer of control from the second block back to the first block the stack depth information is used to set the associating register means so that the required number of extension locations are again reserved for storing the previously accumulated record of execution of the first block. Instead of indiscriminately transferring the record of execution of the first block back to such reserved extension locations, the occupancy and copy indicating storage cells for each such reserved extension location are set to indicate that only the respective memory location is occupied. Thus upon a further transfer of control to another block, the occupancy and copy indicating storage cells provide information used to eliminate unnecessary transfers of words to memory locations already storing the proper words.
摘要:
A display device comprising a panel structure including a plurality of gas-filled cells and including, within the body of the panel, gas communication channels extending between selected cells to provide a selective flow of excited gaseous particles from certain cells to others to prime the receiving cells and thereby control the transfer of glow between the cells.
摘要:
A spring actuated magnetic head positioning system mounted upon an arm extending over the surface of a rotatable magnetic disk is disclosed for advancing the magnetic head into its operating position adjacent the magnetic surface. The spring positioning mechanism is contained within a housing, one end of which resiliently supports the magnetic head. The other end of the housing supports a remotely controlled actuator for actuating the spring positioning mechanism. The spring positioning mechanism is preloaded and held within a fixed and predetermined compressed length when retracted. In its operating position, the spring is translated toward the magnetic disk and further compressed to provide the force necessary to hold the magnetic head in position against the opposing force produced by the air pressure existing between the magnetic head and the rotating magnetic disk.
摘要:
A display panel includes a plurality of dot-like display cells arrayed in rows and columns, with electrodes coupled to the cells in such a way that a plurality of rows or registers of characters can be displayed. Row and column electrodes are coupled to the rows and columns of cells to provide, in each register, a plurality of matrices of cells, each of which can be used to form a character. The panel is operated by selectively firing cells column-by-column, and, to facilitate this operation, the panel includes a column of reset cells positioned adjacent to the first column of cells in the panel and one or more keep-alive cells adjacent to the reset cells. The keep-alive cells are formed by separate anode electrodes and a common cathode electrode which is so constructed and positioned that it does not affect the other electrodes of the panel.
摘要:
An automatic cash dispenser in which the security feature of a system is enhanced by providing the bank or other institution controlling the operation of the machine with the ability to periodically modify the security features of the machine. This flexibility in the security system for the cash dispensing machine includes the provision of the cryptographic input of the cash dispensing system which may be changed by the bank either periodically or as described.
摘要:
A sample peak and hold circuit comprising a dual current source biased by two comparator-driven transistor switches to initially provide a high charging current to a storage capacitor until the capacitor charges to a predetermined percentage of the input signal peak voltage; and then to complete the charging of the capacitor with a lower charging current, until the capacitor charge reaches a magnitude proportional to the input signal peak voltage amplitude. Another transistor switching network is used to discharge the capacitor and an emitter-follower in the output stage prevents premature discharging of the capacitor. Digital logic drives the transistor switches in providing the necessary control functions for charging or discharging the capacitor, or for placing the circuit in a holding condition, as is required within and without successive sampling periods.
摘要:
Form feed device for bookkeeping machines and the like which allows the spacing of two forms of equal or of different width which are positioned side by side, with the spacing of both forms occurring simultaneously or of either one of the two forms alone, and with provisions for making the split variable by the operator when form sizes are to be changed.
摘要:
Display devices adapted to display one or more characters sideby-side in one or more rows and including several groups of display cathode segments positioned in a row, with corresponding segments in each group connected in common, an anode electrode associated with each group of the display segments, and an auxiliary electrode partially surrounding and electrically isolating each group of display segments. The cathode segments, together with an anode, can be selectively energized to display a character at any desired cathode group or position. The auxiliary electrode can be energized to inhibit electrical discharge between the display cathode segments and any other than the associated anode.
摘要:
A memory control unit for determining the actual physical location of an instruction address in one of a plurality of memory units in a digital computer wherein the instruction address and the memory addresses are both in a block, track and word hierarchy, where the instruction address may not correspond to the memory address due to differences in the number of available blocks for recording program instructions from memory unit to memory unit, utilizing: a block address register for storing the block portion of the instruction address; a shift register associated with each memory unit wherein the number of available blocks for each memory unit is stored; a flip flop for bit by bit comparison of the contents of the block address register with the contents of selected shift registers; a counter for shifting from one to another of the shift registers when the contents of the block register exceeds the contents of the selected shift register, and an adder for decrementing the contents of the block address register by an amount equal to the number contained in the previously selected shift register. The memory control unit also includes another flip flop responding to the bit by bit serial comparison of the block address register and the selected shift register for detecting whether the instruction address starts in the last available block in a memory unit, and a circuit for evaluating the track and word portion of the address of each word of the instruction being executed for determining when the last word of an instruction has been executed by the computer.
摘要:
A printing apparatus is provided comprising a plurality of laterally disposed type bars vertically arranged and translatably mounted on a rockable type-bar carrying frame in front of a platen. The type bars are parallel to each other and spaced apart along the length of the platen. A cyclically controlled, driven splined member is laterally disposed and transversely positioned in front of the rockable type-bar carrying frame and below the platen, spanning all of the type bars. On the opposite side of the type bars is a plurality of like number of electrically controlled armature levers, variably timed, for coupling selected ones of the type bars with the splined member thereby to raise the selected type bars into a printing position, following which a pair of cams is operable to tilt the rockable type-bar carrying frame toward the platen to cause the selected type bars to strike against printable material positioned therebetween.