Browse Prior Art Database

Combination Scanner, Priority Circuit

IP.com Disclosure Number: IPCOM000097099D
Original Publication Date: 1962-May-01
Included in the Prior Art Database: 2005-Mar-07
Document File: 2 page(s) / 57K

Publishing Venue

IBM

Related People

Kersey, JR: AUTHOR

Abstract

Fixed-rate line scanning is superimposed upon random-demand lineservicing. As a result, some input lines are connected to a common output line at regular times. Other input lines are connected to the common output line only when they demand service.

This text was extracted from a PDF file.
At least one non-text object (such as an image or picture) has been suppressed.
This is the abbreviated version, containing approximately 63% of the total text.

Page 1 of 2

Combination Scanner, Priority Circuit

Fixed-rate line scanning is superimposed upon random-demand lineservicing. As a result, some input lines are connected to a common output line at regular times. Other input lines are connected to the common output line only when they demand service.

Terminal units are connected to thirty-one low speed LS lines and twelve high-speed HS lines. Each high speed line of the lines 2...5, 7...10 and 12...15 may demand service, via a cable, from the priority circuit. This operates a gate connecting the demanding line and a common output line COL. If more than one high-speed line demands service, service is granted in an order determined by the priority circuit.

The low-speed lines 1...31 are scanned at a fixed rate under control of an oscillator OSC. A counter is stepped in synchronism to record the line currently being scanned. A decoder receives every tenth counter output and generates as a result: (1) an inhibit signal which temporarily prevents the priority circuit from operating any gates and (2) a signal which operates a gate connected to one of the high speed lines 1, 6 or 11, in accordance with the decoder table. Thus, each low-speed line is connected to the common output line at a fixed time.

During a first scan, the common output line is connected to the scanner, via high speed line 1, when the low-speed lines 1 and 31 are scanned. Demands from high speed lines are not serviced at these two times due to the operation of the...