GB1438392A - Control device for tabulation printing - Google Patents

Abstract

1438392 Control of printers CASIO COMPUTER CO Ltd 13 Dec 1973 [13 Dec 1972] 57896/73 Heading G4H A printer includes means for printing data in tabulated columns in which numerical and alphanumerical data are respectively right- and left-justified. Bits are entered by means of a keyboard 10 in a circulating register 13 in positions corresponding to the column-defining tabset positions (e.g. 10, 20, . . . , Fig. 4A). A bit in a register 14, circulating synchronously with the contents of 13, indicates the position of the printhead 12 (or paper, if this is being moved instead), both being stepped by signals S3a, S3b from an OR gate 19. Data S7 is fed to a buffer 11 (whence it is fed one character 32 at a time to the printer) and to a discriminator 16, Fig. 2A (not shown), whose output S9, S10 indicates whether the data is wholly numeric or not. For numeric data, a bit is entered in a circulating register 15, Fig. 4C, in a position corresponding to the righthand tabset position of the column being printed. A signal S15 then enters bits in the positions corresponding to those where data will be printed (e.g. a 3-digit number in Fig. 4D). A signal S12 then causes a control circuit 36, Fig. 2C (not shown), to output a signal I which sets a flip-flop 38 to provide stepping signals S3a, S3b. When the bit in register 14 has been shifted to the position of the first bit in register 15, gate 47 is enabled and flip-flop 38 is reset. In response to an output reset signal from 38, circuit 36 generates outputs II (opens gate 33 to allow the first character to be printed), III (shift one position) and IV (to gates 41, 42). Gate 42 is blocked by a signal from a circuit 43 until the outputs from 13, 14 coincide; meanwhile the output S13 from gate 41 causes the output of signals II-IV to be repeated until printhead 12 reaches the tabset position (Figs. 4E-4H): now gate 42 is enabled, and its output S14 clears 15 and 16, ready for the next column to be printed. When alphanumeric data is being printed, discriminator 16 does not set flip-flop 38, so that the printhead is not continuously stepped forward, and register 15 has no effect. Thus the first character is printed immediately after the lefthand tabset position for that column, by signals II-IV from circuit 36. The registers may be replaced by counters and keyboard 10 may be replaced by a computer.