Browse Prior Art Database

Printer Interface

IP.com Disclosure Number: IPCOM000042167D
Original Publication Date: 1984-May-01
Included in the Prior Art Database: 2005-Feb-03
Document File: 1 page(s) / 11K

Publishing Venue

IBM

Related People

Hsieh, DM: AUTHOR [+3]

Abstract

This article shows and describes logic for providing communication between a printer which requires bidirectional data flow and a using device which normally accommodates unidirectional data flow only. In the figure, the using system is represented on the left, and the printer on the right. The using system, which, for example, may be a small computer, includes twelve output lines and five input lines. The printer, on the right, requires a bidirectional data bus and five control lines. The figure illustrates the data flow as well as control lines. The using system sends eight bits of data based on the status of the Output Buffer Full (OBF) signal, and sets the OBF flip-flop.

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Printer Interface

This article shows and describes logic for providing communication between a printer which requires bidirectional data flow and a using device which normally accommodates unidirectional data flow only. In the figure, the using system is represented on the left, and the printer on the right. The using system, which, for example, may be a small computer, includes twelve output lines and five input lines. The printer, on the right, requires a bidirectional data bus and five control lines. The figure illustrates the data flow as well as control lines. The using system sends eight bits of data based on the status of the Output Buffer Full (OBF) signal, and sets the OBF flip-flop. When the printer reports a response or status based on the status of the Input Buffer Full (IBF) signal and sets the IBF flip-flop, eight bits of data in two four-bit segments are latched in latches A and B. The using system then uses four of its five input lines to receive four bits from each of the latches A and B, and resets the IBF flip-flop. Multiplex logic and control is used to report IBF/OBF status.

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