Over the back: Difference between revisions

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'''Over the back''' or '''over the top''' are terms used to describe an alternative connectivity [[data path|path]] between two more more boards plugged into a [[backplane]]; i.e. not using the [[bus]] carried by the backplane.
'''Over the back''' or '''over the top''' are terms used to describe an alternative connectivity [[data path|path]] between two more more [[printed circuit board|boards]] plugged into a [[backplane]]; i.e. not using the [[bus]] carried by the backplane.


On the board edge opposite to the 'fingers' which plug into the backplane, a [[flat cable]], or in some cases a small [[printed circuit board]], with a pair of connectors plugs into [[Berg connector]]s each board.
On the board edge opposite to the 'fingers' which plug into the backplane, a [[flat cable]], or in some cases a small [[printed circuit board]], with a pair of connectors plugs into [[Berg connector]] headers each board.


In a few cases (e.g. [[PDP-8 family|PDP-8]] [[main memory]]), instead of connectors, the back edge of the boards ''also'' has contact fingers, and what is effectively a small plug-on backplane is used to connect the cards.
In a few cases (e.g. [[PDP-8 family|PDP-8]] [[main memory]]), instead of headers, the back edge of the boards ''also'' has contact fingers, and what is effectively a small plug-on backplane is used to connect the cards.


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[[Category: Components]]
[[Category: Components]]

Revision as of 13:26, 23 August 2021

Over the back or over the top are terms used to describe an alternative connectivity path between two more more boards plugged into a backplane; i.e. not using the bus carried by the backplane.

On the board edge opposite to the 'fingers' which plug into the backplane, a flat cable, or in some cases a small printed circuit board, with a pair of connectors plugs into Berg connector headers each board.

In a few cases (e.g. PDP-8 main memory), instead of headers, the back edge of the boards also has contact fingers, and what is effectively a small plug-on backplane is used to connect the cards.