GB1334679A - Electronic computer with peripheral printing unit - Google Patents

Abstract

1334679 Printing ING C OLIVETTI & C SpA 25 Nov 1970 [25 Nov 1969 25 Sept 1970] 56150/70 Heading G4H In a combination of an electronic computer with a peripheral printing unit which unit includes a plurality of cyclically-movable printing elements, each adapted to print one of a set of characters on a recording support during each cycle, the computer includes code converting means for producing successive words for controlling the operation of the printing elements, each bit of a word corresponding to one of the printing elements. As disclosed, 8 type wheels, each bearing a full font, are spaced along the print line and rotate continuously about an axis perpendicular to the print line, being carried on a carrier reciprocating along the print line, so that during forward movement of the carrier, each type wheel can print a character in 16 consecutive positions on the line in respective revolutions of the type wheel, to give a line of 128 print positions, a second line being printed during reverse movement of the carrier. Each revolution of the type wheels, the printing unit causes a microinterruption of the computer (which is microprogramme-controlled) to cause the 8 characters required to be printed on the next revolution of the 8 type wheels to be read from the computer core memory, each character being used to address the microprogramme read-only memory to produce a microprogramme which inserts a bit in a set of 48 words, each of 8 bits, in the core memory to indicate the character, one word corresponding to each character in the font and the 8 bits of the word corresponding to respective type wheels. As each character comes into printing position during rotation of the type wheels, a microinterruption causes the appropriate one of the 48 words to be read from the core store and supplied via an 8-bit register in the printing unit to hammer drivers, one per type wheel, each driver receiving a respective bit of the word.