Browse Prior Art Database

Dynamically Conditionable Channel Circuitry

IP.com Disclosure Number: IPCOM000090654D
Original Publication Date: 1969-Jun-01
Included in the Prior Art Database: 2005-Mar-05
Document File: 2 page(s) / 42K

Publishing Venue

IBM

Related People

Berkebile, HE: AUTHOR [+3]

Abstract

Microprogramming of the elemental units of a computer provides a great deal of flexibility. Various functions can be performed by microroutines instead of dedicated hardware. There can be an election to implement a particular function in either hardware or a microroutine. Certain advantages and disadvantages accompany a selection of either.

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Dynamically Conditionable Channel Circuitry

Microprogramming of the elemental units of a computer provides a great deal of flexibility. Various functions can be performed by microroutines instead of dedicated hardware. There can be an election to implement a particular function in either hardware or a microroutine. Certain advantages and disadvantages accompany a selection of either.

This system is another arrangement for implementing a function. In the case of a computing system having a control program, microinstructions, resident in control storage area 1 of main storage 2, it is necessary to load the control program into storage before the system is used. This control program is usually contained on a disk file or a deck 3 of unit record cards.

Assuming that the I/O function, particularly the channel, is the one to be implemented, a specific card 3n in deck 3 is punched to indicate whether the system is to operate with a selector channel or a multiplex channel. During the initial control program load ICPL, a card reader is effective to supply the data from the cards to storage data register 4. As part of the ICPL routine, the data from card 3n is transferred from register 4 via gate 5, under the control of a particular bit in control register 6, to set channel identification latch 7 to the appropriate state.

Depending on the state of latch 7, either multiplexor line 8 or selector line 9 is conditioned to indicate the mode of channel operation which is selecte...