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Browse Prior Art Database

Automatic Storage Quantity Characterization Feature

IP.com Disclosure Number: IPCOM000051301D
Original Publication Date: 1981-Jan-01
Included in the Prior Art Database: 2005-Feb-10
Document File: 3 page(s) / 94K

Publishing Venue

IBM

Related People

Grimes, DW: AUTHOR

Abstract

A storage feature is described that eliminates manual intervention with jumpers and pins on each installed card, thus increasing reliability of all the cards and eliminating human errors when installing the jumpers for addressing the cards. It prevents errors such as addressing storage cards that are not installed.

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Automatic Storage Quantity Characterization Feature

A storage feature is described that eliminates manual intervention with jumpers and pins on each installed card, thus increasing reliability of all the cards and eliminating human errors when installing the jumpers for addressing the cards. It prevents errors such as addressing storage cards that are not installed.

Storage expansion cards can be added to a computer system in order to increase the main storage capacity. The processor typically located on the main central processing unit (CPU) card, must be able to detect that a valid memory expansion card, which is actually installed, is being addressed. If not, it must inhibit the memory cycle.

A typical method of accomplishing the communication of memory quantity to the CPU is by the presence or absence of jumpers on pins located on each card. This system causes a reduction in reliability by the high potential failure rates of such mechanical devices. The present scheme eliminates the mechanical jumpers and pins and their associated failures, costs, and manual intervention and its induced human errors in jumpering and addressing. A small amount of logic is installed on each card. This logic is identical on all cards to allow only one part number card to be used for all storage expansion cards. The logic on each card performs a different discrete function on each card since the inputs to each card are different even though the logic is the same on all cards.

Fig. 1 is a block diagram of the feature. The logic that performs this function on each expansion card is in Fig. 2. Fig. 3 illustrates the logic levels, from the logic on one card to the logic on the next card, and sequencing of information bits fr...