Patent GB-902094-A (GB)
Title: Improvements in or relating to data recording apparatus
Inventor: WHITE HARRY SIDNEY
Filed: 1957-12-11
Abstract: 902,094. Selective printing. INTERNATIONAL COMPUTERS & TABULATORS Ltd. Nov. 13, 1958 [Dec. 11, 1957], No. 38491/57. Class 100 (4). [Also in Group XXXVIII] Apparatus for checking the transfer and translation of data characters received in a first code and transmitted to an output device in a second code comprises a code translator, means for generating a first signal each time a character signal in the first code is received, means for generating a second signal indicating the operation of the output device, and an error indicator receiving the first and second signals and giving an output unless one and only one character is registered by the output device when the first signal is received. Fig. 4 shows the reading of data characters from columns of a punched record card 19 by electrical contact brushes 23; there are two perforations in each correctly punched column, and the positive potential from supply 22 on two input lines to a decoder 2 energizes a single relay 9a ..., which operates a typewriter key (Fig. 3, not shown). Only three key relays are shown; for operating all the keys of a conventional typewriter more than four perforation positions would be necessary. Each key has contacts 16a ..., which are closed on operation to energize one coil of a balanced relay ER, the other coil of which passes a current (fixed by resistor 25 independent of the number of perforations sensed) at each sensing. Resistors 26 are chosen so that if a single key is operated the relay is balanced and does not operate; if as a result of faulty sensing or perforation one, or more than two, of the input lines to decoder 2 are energized then no, or more than one, key will be operated, the relay will be unbalanced, and contacts ERa will close to give a visible error signal at 27 and discontinue card feed. Fig. 5 shows a similar card-sensing arrangement, decoder 2, and typewriter key solenoids 9, but in this system the contacts 16a ... of the keys are arranged to energize one of the inputs to a recoder 7 which gives an output in the original card punch code (in this case a " 2 out of twelve " code). Balanced relays such as R1 and R2 are provided for each of the card code lines and if the original and recoded characters do not correspond the contacts R1a, R2a ... of one of these relays will close to energize alarm relay R3. If more than one key is operated only one (the leftmost) of the inputs to 7 will be energized, but the relay R3 will be energized directly over contacts 16a ..., and 41b .... The characters read from the card 19 are, in addition to being printed by relays 9, entered by punch magnets PM (one for each of the sensing brushes 23) on a further card, and the card feed may be stopped at any desired column to allow information typed manually on the keyboard to be also entered on this further card. The card feed is stopped by a programme relay PR energized over a plug board connection 34 by a brush 31 mounted on the card reader carriage and contacting segments 32 in turn as columns of 19 are read. When coil 35 of PR is energized the punch magnets PM are switched by contacts such as PRa and PRb from the sensing brushes 23 to the output of recoder 23 for punching of typed characters, and contacts PRe are opened to disable the error relay R3. Relay PR is tripped by energization of coil 36 at a predetermined columnar position of the card punch to restore the original connections. The checking system may be applied to the reading of punched tape, magnetic tape, or printed records instead of punched cards, and to output devices such as punched tape, or magnetic drum or core stores of a computor. The card feeding, sensing and punching is generally similar to that described in Specification 562,278.