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Data Transfer between Intelligent Terminal Controller Systems and a General Purpose Computer Channel

IP.com Disclosure Number: IPCOM000087129D
Original Publication Date: 1976-Dec-01
Included in the Prior Art Database: 2005-Mar-03
Document File: 1 page(s) / 11K

Publishing Venue

IBM

Related People

Duffie, CA: AUTHOR [+3]

Abstract

Improved buffer management at an intelligent controller can be provided across a general-purpose computer channel, without changing the channel architecture. The existing I/O interface, comprising channel commands status and sense information, is treated as a set of primitives and used to define the linear combination of those primitives to indicate the new functions of Exit Buffers Depleted and Exit Buffers Depleted With Data to Send.

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Data Transfer between Intelligent Terminal Controller Systems and a General Purpose Computer Channel

Improved buffer management at an intelligent controller can be provided across a general-purpose computer channel, without changing the channel architecture. The existing I/O interface, comprising channel commands status and sense information, is treated as a set of primitives and used to define the linear combination of those primitives to indicate the new functions of Exit Buffers Depleted and Exit Buffers Depleted With Data to Send.

Exit Buffers Depleted is signaled to the host computer across the channel, by the combination of device end and status-modifier status bits, and placed in the channel status word to indicate that the buffers are again free, and the Write commands from the host computer can again be initiated. If on the other hand the buffers are still depleted but the controller has data to send to the host in some of the buffers which when transmitted will alleviate the buffers depleted condition, the combination of device end, status modifier and attention can be signaled to cause the I/O supervisor to schedule the appropriate channel program to read the buffers.

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