GB1438391A - Control device for tabulation printing - Google Patents

Abstract

1438391 Tabulation printing CASIO COMPUTER CO Ltd 20 June 1973 [22 June 1972] 29344/73 Heading G4H A control device for tabulation printing comprises synchronously circulating registers 13, 14 which respectively store tab positions 10, &c. Fig. 3A, and the position of a print head 12, and a circulating register 15 which stores the number of characters to be printed in their correct positions between two selected tab positions (Fig. 3D). As described, the number "145" is to be printed between tab positions 10 and 20 with digit "5" in position 19. The tab positions (Fig. 3A) are entered in register 13 as follows: signal 52 from a keyboard 10 steps register 14 and print head 12 (signals 53a, 53b) through 10 positions signal S1 then enables gate 16 so that the bit circulating in register 14 is entered in position 10 of register 13. Tab positions 20, &c. are entered in register 13 in the same way, and 14 and 12 are stepped back to their initial positions by a signal S4. Next, tab position 20 is entered in register 15: head 12 and register 14 are stepped to position 10, when the outputs from 13, 14 are both "I" and enable gate 21. A flip-flop 22 is set, and its output delayed by 1 bit time at 23 then fed to gate 24. When the head reaches position 20, the output from 13 provides the second input to gate 24 whose output (together with a "head stopped" signal S6) enables gate 25 to enter a bit in position 20 of register 15. The number to be printed ("145") is entered (signal S7) from 10 and stored in a buffer 11, while a signal S11 is fed to gate 43 to establish a circulation path for register 15 so that 3 bits (corresponding to the 3 digits 1, 4, 5) are entered to the left of the tab position 20 bit in 15. A signal S8 is then sent to a control circuit 34, whereupon a signal I sets flip-flop 35 to produce signals S3a, S3b again. When the bit in 14 coincides with the first bit in 15, gate 37 is enabled, flip-flop 35 is reset and the head stops in the first printing position. A signal II then opens gate 33 and the character "1" is printed. A signal III shifts the head and the register 14 to the right, and a signal IV enables gate 38 since the "1" bits in 13, 14 do not coincide; S9 causes II, III and IV to be generated twice more, and "4" and "5" are printed. The last signal IV causes gate 39 to be enabled since the "1" bits in 13, 14 coincide at tab position 20, and a "print end" signal S10 is produced. Gate 29 is closed and gate 25 is opened so that the next tab set position 30 can be stored in register 15 ready for the next printing operation. Data may be input from a calculator rather than from a keyboard, and register 14 may be a counter. Provision may be made for moving the print medium rather than the print head.