GB1015325A - A control unit for a digital program-controlled computer - Google Patents

Abstract

1,015,325. Digital computers. TELEFUNKEN PATENTVERWERTUNGSGESELLSCHAFT m.b.H. July 13, 1962 [July 14, 1961], No. 27116/62. Heading G4A. In a computer comprising a plurality of peripheral units, each unit has a bi-stable member for indicating that access is required, setting of any of these members causing the computer programme to be automatically interrupted while the peripheral unit is transferring data. The computer described includes a store 2, an arithmetic unit 3, a control unit 1 and four peripheral input-output magnetic tapes 4-7. The computer word length is 48 bits and the computer operates in the parallel mode. A channel selector 8 scans the indicator flip-flops 28 in the four tape units sequentially. The control unit 1 includes a 16-bit address register 9 and an operation register 10. Data is stored on the peripheral tapes in six parallel tracks. In an instruction for transferring data from one of the peripheral tapes 4, for example, to the computer store, the number of words to be read is entered in a register 11 in the control unit and the first effective store address is entered in a register 14. The " read from tape 4 " operation digits in register 10 are effective via the microprogramming circuit 26 to set a " priority " flip-flop 30 and a " read " flip-flop 29 in the tape circuitry and to store the initial address and the number of words in an index store 13. The computer then continues with other instructions until a buffer register 27 in the circuitry of the tape 4 is filled thereby setting the associated indicator flip-flop 28. When the channel selector 8 senses this set flip-flop, it stops thereby setting a bi-stable circuit 32 which is interrogated at intervals by the microprogramme circuit 26. When the circuit 32 is thus found to be set the current computer programme is interrupted, the contents of the registers 9, 11 and 14 being temporarily transferred into one of two registers 19, 20 associated with the computer storage sections SP1, SP2, this data being re-transferred to the registers 9, 11, 14 when the transfer from the tape 4 has been effected. Circuit details.-The various registers are composed of bi-stable transistor circuit stages actuated in response to computer clock pulses. The wiring of the computer is provided on " crossbar plates " which consist of insulating plates having a set of parallel conductors on one side and a perpendicular set of parallel conductors on the other side, the two sets being connected appropriately at various crosspoints either directly or via resistors or diodes. The microprogramme circuit 26 also consists of such crossbar plates (Figs. 11, 12, not shown).