GB1318452A - Data-processing apparatus for business machines using punched-tapes - Google Patents

Abstract

1318452 Record tape controlled printing machines KOMBINAT ZENTRONIK VEB 24 Aug 1970 40686/70 Heading G4H In a system for feeding data to a printing machine or an accounting machine two tape readers are used, one tape containing a series of blocks of data identified by addresses and the other a series of addresses specifying the desired blocks of data, and decimal digits are used as the addresses, the desired addresses being entered into a shift register and transferred in turn to the input of the comparator, the addresses road from the data tape also being applied digit by digit to the comparator, the arrangement being such that when a preset number of decimal digits have been compared the comparison is terminated, agreement allowing the associated data block to be read out to the printer or accounting machine. Address characters on the data block are distinguished by being preceded and followed by a special mark character which, when detected, sets a trigger initiating the above mentioned comparison operation. The address digits read from the "desired address" tape are entered in turn in 8-track tape code into eight triggers 25-28 &o. Fig. 1 by signals at 58-61, &c. Alternatively desired addresses may be entered on inputs 62-65 &c. from a keyboard or other equipment. Each digit in turn passes from triggers 25-28 &c. to other groups of triggers forming the shift register (Fig. 5, not shown). During a comparison the digits are stepped through the original group 25-28 &c. in synchronism with the reading of the address digits from the data tape, these being entered in turn into triggers 17-20 &c. Shifting of the data is under the control of pulses derived from a brush reading the sprocket holes on the tape. During a comparison operation these pulses are counted in a digit counter which is preset to the number of significant digits in the address. If the comparator has not produced a disagreement by the time the preset counter gives an output the data of the corresponding block is read-out. If a disagreement signal is produced the comparison operation is terminated and the data tape steps to the next address. Some only of the digits may be used for example the highest three, the counter then being preset to this number and the stored address rapidly cycled to the home position after each comparison. In this case all blocks of data having these address digits will be selected. The comparator (Fig. 1C not shown) comprises a series of AND NOT gates receiving corresponding outputs from the triggers 25-28 &c., and 17-20 &c., all connected through an OR gate to a trigger which sets when any of the stored bits disagree.