Dismiss
InnovationQ will be updated on Sunday, Oct. 22, from 10am ET - noon. You may experience brief service interruptions during that time.
Browse Prior Art Database

Enhanced Riser Card with Expansion Function Capability for Personal Computers

IP.com Disclosure Number: IPCOM000113087D
Original Publication Date: 1994-Jul-01
Included in the Prior Art Database: 2005-Mar-27
Document File: 4 page(s) / 149K

Publishing Venue

IBM

Related People

Eng, RC: AUTHOR [+4]

Abstract

Described is a hardware implementation to provide enhanced functions for Personal Computers (PCs) by placing expansion functions on a riser card for interfacing to a planar board.

This text was extracted from an ASCII text file.
This is the abbreviated version, containing approximately 42% of the total text.

Enhanced Riser Card with Expansion Function Capability for Personal
Computers

      Described is a hardware implementation to provide enhanced
functions for Personal Computers (PCs) by placing expansion functions
on a riser card for interfacing to a planar board.

      In a typical PC, printed circuit boards are used to hold the
bulk of the electronic circuitry.  A large printed circuit board,
generally referred to as a planar board, is used to hold the
circuitry required to operate the basic functions of the computer.

      Since the basic computer functions are performed by the
circuitry on the planar board, a number of additional tasks must
occasionally be added, such as larger data storage capability,
optical disk devices, and a variety of printing devices to support
printed output.  A wide variety of Input/Output (I/O) devices have
specific circuit requirements to allow the PC to control the
operation of, and interface with, specific I/O devices.  Typically,
the particular work a PC is used for will dictate the types of
required I/O devices.

      However, it is inefficient to include circuitry on the planar
board as a standard feature to support specific types of I/O devices,
or a specific optional function.  This inefficiency has led to the
development of printed circuit adapter cards which hold the circuitry
for a specific function, such as controlling a printer or storage
device and interfacing that device with the planar board, or any
other desired function.  Adapter cards typically have edge connectors
with electrical contacts which can be plugged into a connector on the
planar board.  However, this adds adapter card connector circuitry to
the circuitry of the planar board.  In addition, adapter cards which
connect to I/O devices usually have an I/O connector on an edge of
the card which allows a cable to be connected between the I/O device
and the adapter card.  Some planar boards had multiple connectors to
attach to multiple cards.  While the plane of the adapter card would
be perpendicular to the plane of the planar board, it is not required
to be perpendicular, and may in fact be oriented at any angle
convenient for packaging purposes.

      The Basic Input/Output Software (BIOS) in the PC is generally
closely tied, and is typically a component, of the planar board.  The
rapid turnover of planar boards in the PC's and the economic factors
derived from their volumes has led the BIOS to be a base common
denominator of functionality across planar boards.  Each new planar
board normally requires a new version of BIOS specific to the planar
board implementation.  Any custom enhancements to the system BIOS for
a given planar will result in a unique BIOS that is obsoleted by the
next generation of planar boards.  It is economically inefficient to
customize a planar BIOS since the next planar generation makes the
customization obsolete and requires another unique BIOS with the
customization to be g...