Patent GB-1164379-A (GB)
Title: A Device for the Programmed Transmission of Data Groups.
Inventor: KUTSCHBACK ERNST
IPC: G06F3/08
Filed: 1967-05-03
Abstract: 1,164,379. Data input control. BUCHUNGSMASCHINENWERKE KARL - MARXSTADT VEB. 3 May, 1967, No. 20603/67. Heading G4A. Data recorded on a data carrier in serial manner may be skipped, during reading, until a predetermined character is detected. The character to be searched for is included in the read instruction. As described, a punched paper tape reader having data channels 51 is connected to a data processor having an input channel 101 by way of a control unit shown in Fig. 2. The data on the tape is divided into words, sentences and blocks by predetermined marks which may be used to control the reading of the tape. The tape may also include control signals and may be read forwards or backwards. Control Unit features.-The operation of the tape feed is controlled by a bi-stable trigger stage E2 in such a way that when output line 12 is true (binary 1 signal) the feed is stationary and when line 12 is pulsed (binary 0 signal) it is running. The line 12 is connected to the tape feed by way of a self-holding circuit 35-38 and a line 52. The data channel 51 is connected through self-holding circuits 50 the operation of which is controlled by signals on lines 25 and 10. Signals generated by sensing of sprocket hole are passed by way of lines 9 and 10 to the clock pulse trigger stage B3. Clock pulses are issued on lines 2 and on line 102 to the processor. Non-selective data input.-The control unit is prepared for tape reading by a preliminary instruction from the data processor on channel 104. The operation part of this instruction after decoding by an instruction interpreter B2 causes a change-over stage B1 to connect processor lines 101-103 to lines 1-3, lines 201-203 to which lines 101-103 are normally connected being connected to a further peripheral device, not shown. Interpreter B2 then issues a confirmation signal to the processor on a line 105 and this signal causes the clock pulse trigger stage B3 to issue a clock pulse. In this mode of operation the preliminary instruction address part is inoperative and the preliminary instruction ends there. After a pause, the processor issues an input instruction via line 103. Interpreter B2 which is connected to stage B1 by line 3 then issues a confirmation signal as before. The clock pulse which triggers stage B3 issues (as before) now opens an AND-gate which by way of line 19 sets bi-stable stage E2 so as to start the tape feed running. The changing of the signal on line 12 prevents the confirmation signal from being terminated. The data from channel 51 is passed in parallel by way of a branched channel 11 to a data decoder D1, a mark decoder and comparator D2 and a control signal decoder D3. The data read passes to the processor by way of channels 1 and 101 until decoder D3 detects a control signal to terminate reading, whereupon line 18 carries a true signal which opens gate 29 to reset the trigger stage E2. The confirmation signal then ends and the input instruction is terminated. The last character read (the control signal) is held in circuits 50. Selective data input.-The address part of the preliminary instruction now specifies a mark to be searched for. This mark is passed by way of channels 104 and 4 to mark decoder and comparator D2. When the preliminary instruction clock pulse is issued by stage B3, an AND- gate is opened which by way of line 20 sets the stage E2 to start the tape reader running. This continues until a character is read which matches the mark in decoder D2. Line 15 then becomes true, stage E2 is reset by way of line 21 and the tape feed stops. The confirmation signal then ends and the preliminary instruction is terminated. The input instruction proceeds as before.