Browse Prior Art Database

Data Generator and Sequencer

IP.com Disclosure Number: IPCOM000075389D
Original Publication Date: 1971-Sep-01
Included in the Prior Art Database: 2005-Feb-24
Document File: 2 page(s) / 41K

Publishing Venue

IBM

Related People

Mersel, DR: AUTHOR [+2]

Abstract

In the testing of display terminals which normally operate from a processor through a control unit, a logical configuration for simulating a computer test of a display terminal off-line and thereby avoid the time and expense involved in an on-line test with the computer and control unit operates as follows.

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Data Generator and Sequencer

In the testing of display terminals which normally operate from a processor through a control unit, a logical configuration for simulating a computer test of a display terminal off-line and thereby avoid the time and expense involved in an on-line test with the computer and control unit operates as follows.

Referring to the drawing, time pulse distributor 1 generates a thirteen-bit pulse sequence, a thirteen-bit word being used for control and data information, which is applied to associated switching banks 1, 2 and 10 representing three of the ten switching banks normally used in the test. Each of switching banks 1, 2 and 10 include thirteen logical AND circuits, each having a toggle switch in one leg which are manually set in accordance with a desired pulse pattern.

In testing, both control and command words, as well as data words, are simulated for a complete test, since the operation of the display terminal on-line requires a specific control sequence preceding and following data transmission. By way of example, a typical data sequence would be initiated by a general poll followed by a poll with acknowledge, followed by a WRITE command. The displayable data could be preceded by field designator or field separator identifiers followed by the display data. At the end of each sequence from time pulse distributor 1, a step pulse will be applied to the eleven-bit counter 9 which provides ten outputs, each output being connected to an a...