Browse Prior Art Database

Pc-To-System-Bus Connection for Multiprocessing and Increased I/O

IP.com Disclosure Number: IPCOM000036916D
Original Publication Date: 1989-Nov-01
Included in the Prior Art Database: 2005-Jan-29
Document File: 2 page(s) / 39K

Publishing Venue

IBM

Related People

Malbacher, JC: AUTHOR [+2]

Abstract

This article describes a circuit arrangement which provides a mean combining the advantages of an industrial personal computer (PC) with the advantages of a secondary bus.

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Pc-To-System-Bus Connection for Multiprocessing and Increased I/O

This article describes a circuit arrangement which provides a mean combining the advantages of an industrial personal computer (PC) with the advantages of a secondary bus.

The drawing shows the architecture of this disclosure. PC feature card A controls and drives PC processor signals over cable B to and from secondary driver card C. The PC card provides for decoding and generating signals to the secondary bus which accesses the secondary I/O and memory areas. This happens whenever a preprogrammed area in the host PC memory space is accessed. There are circuits on the board which allow for wait states when accessing secondary memory or when accessing secondary I/O. Since not all PC control signals have equivalent secondary bus control signals, there is circuitry to derive and sequence these new signals. Additional circuitry allows for notifying software in the host PC when the secondary bus power supplies are on and when the bus has been reset. Special registers allow the PC software to access contiguous areas of secondary bus memory or to access sixteen different blocks at a preprogrammed offset in each of sixteen segments of the one megabyte secondary bus address space. This latter feature assists the host PC in using secondary bus pro cessor cards in a multiprocessing environment such that each card can be read and written without relocating the memory map. The PC card also may be jumpered to use either eight or sixty-four kilobytes of the first megabyte of PC memory, and has a control register t...