Browse Prior Art Database

I O Interface Tag Lines

IP.com Disclosure Number: IPCOM000088500D
Original Publication Date: 1977-Jun-01
Included in the Prior Art Database: 2005-Mar-04
Document File: 1 page(s) / 11K

Publishing Venue

IBM

Related People

Moyer, JT: AUTHOR [+3]

Abstract

IBM System/36O-370 Input/Output (I/O) Interface lines include three tag lines and either three or four selection control lines relative to each direction of data transfer. These lines are used for control and synchronizing purposes. Operations of these lines in each group are relatively exclusive, meaning that only one tag line and/or one selection control line can be active at one time.

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I O Interface Tag Lines

IBM System/36O-370 Input/Output (I/O) Interface lines include three tag lines and either three or four selection control lines relative to each direction of data transfer. These lines are used for control and synchronizing purposes. Operations of these lines in each group are relatively exclusive, meaning that only one tag line and/or one selection control line can be active at one time.

A point to note is that this relative exclusivity is not essential and, in fact, may be undesirable in high data rate transfers over "long" distances. It may be more reliable to digitally encode the tag and selection control information and transfer the encoded information along with parity check information, thereby, for instance, avoiding uncertainties due to unequal propagation delays or line noise.

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