Patent GB-1279491-A (GB)
Title: A terminal device for the transmission of data with display
Inventor: BARTOCCI ANTONIO
IPC: G06F3/02
Filed: 1969-09-08
Abstract: 1279491 Cathode-ray tube character display ING C OLIVETTI & C SpA 8 Sept 1969 [23 Oct 1968] 44346/69 Headings H4F and H4T A cathode-ray tube display arrangement for data characters received in succession in register 39 (Fig. 4) comprises a decoder 54 producing vertical and horizontal deflection voltages SCV, SCO to select an area of matrix 59 of a charactergenerating tube on which the character is formed, generators 61, 63 producing sawtooth and sinusoidal voltages to cause scanning of that area, and an amplifier 66 receiving the secondary emission signals from matrix 59 and impressing them on the display tube beam as an area is scanned by vertical sine-wave signals derived from 68 and by horizontal sweep signals to paint up to 56 characters in a line, and also by a vertical step function to paint up to 16 lines. The character format is a 10-bit one with in addition to the seven character-defining bits shown in register 39, a parity bit and two control bits used to enable tagging of the next character for display or entry to store, and one of these bits (b s ) is used to control the successive entry of characters into the data store. The use of characters representing shift or tabulation orders enables forward and backward spacing, tabulation, shift and other formatting under control of either an input keyboard or signals from a central processor. Fig. 3 illustrates a data terminal in which the entry is from keyboard or central processor into a delay-line recirculating memory with output and input transducers 26, 28. The memory has a capacity of 1024 characters of which 8 in each 64 are unused to allow for CRT line-flyback time. Characters are entered, modified or read out at register 27 forming part of the memory loop and clock signals CLO1 control the shift of data bits. Keyboard entry.-Characters are keyed at 31 and if the system is free for keyboard entry (signal LITA) are transferred to register 34 (FIPR records this) and subsequently, at bittime D1, to REM 3-0 of register 27 into the character position for which bs=1 as shown by signals REM 7 and D5 occurring together at gate 35. The bit bs in this character position is set to zero by closure of gate 37, and entered as one in the following character via gate 107 for control of keying-in of subsequent data. Computer entry to store.-Signal SPOC indicating "assigned to processor" sets FRIC to allow characters from the computer to enter RU21- 28 of register 39. FCP2 records the fill of 39 and via gates 43, 44 transfers the character to 34, and sets FIPR to reset FCP2. Characters are then transferred to store as above. Transfer of data to computer.-A special character keyed at 31 is recognized by 45 to block the setting of FIPR and set FUTR and FEST to produce a signal MAUL which opens 49 to transfer the character tagged at bit b1 from 27 to 39. This tag b1 is used for control of computer input characters. MAUL also zeroes b1 and a "1" is entered into the next character via FIUL. The character is transferred via 44 (enabled by CRU2) to 34, subsequent tagged characters being also shifted via 39 and 34 to the computer. When the terminal is "free" or "assigned to keyboard" characters in the delay line are successively copied from 27 to 39 for display.  Format and tabulating functions.-The generating of the necessary signals for controlling the shift of the bit bs=1, for obtaining the various format, shift, cancel, and tabulating functions is described in detail and illustrated in Figs. 5 and 6 (not shown).