+---+
     | R |
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REAL TIME CLOCK (RTC)

First included on the IBM PC AT in 1984.  Originally
based on the Motorola MC146818A RTC chip, the
functionality has been duplicated in subsequent
chipsets and compatible components. It is essentially a
wristwatch quartz crystal that provides time and date
down to the second and up to the year.

The RTC is a separate device, it functions as a battery
operated clock and every complete second updates the
CMOS memory.  Continues to operate when main power is
off.  Generally only used at boot time to set the
System clock.  Some (very few) applications read RTC
direct.

Provides a two digit year count. Has no internal
storage, but provides base for results stored in CMOS
NON VOLATILE MEMORY.

RECOVERY TESTING

Testing aimed at verifying the system's ability to
recover from varying degrees of failure.(BCS)

REGRESSION TESTING

Selective retesting to detect faults introduced
introduced during modification 0f a system or system
component, to verify that modifications have not caused
unintended adverse effects, or to verify that a
modified system or system component still meets its
specified requirements.  (IEEE 729-1983)

Retesting of a previously tested program following
modification to ensure that faults have not been
introduced or uncovered as a result of the changes
made.(BCS)


REMEDIATION

This concept embodies one or more processes to repair
or eliminate malfunctions relating to year 2000 date
data handling under a pre-determined set of criteria.
The following is a non-exhaustive list of possible
remedies:

* expanding the year field to four digits (field
expansion)

* encoding four-digit year information into an existing
field (encoding)

* using a 100-year logic window (window)

* employing a date data bridge that converts date
formats (bridge)

* replacing one or more system elements (replacement)

* retiring the system (elimination)

The industry currently reflects strong consensus that
there is NO ONE fix for all applications.  A range of
fixes can, and will most likely, apply.  Fixes will be
dependent on the operating environment and the
prevailing factors within, such as the degree of
interface the application has with other applications,
or the level of date data processing within or across
applications.
(IEEE)

REPLACEMENT

 (also called Migration)

A process which requires the retirement of a system or
system element which is determined to be necessary, but
will not be made Year 2000 compliant.  The system,
system element, or data is moved to an alternate Year
2000 compliant system or system element.
(IEEE)

REPLACEMENT VIA COMPLIANT PACKAGES

The most obvious substitution strategy is to replace a
non-compliant application with a newer commercial
package that is already year 2000 compliant.  This
strategy works only for applications which have
commercial equivalents, so it is obviously no help for
proprietary or highly customized software.

REPLACEMENT VIA CUSTOM DEVELOPMENT

In situations where aging legacy software is due for
replacement, it may be possible to accelerate the
development of new applications that are year 2000
compliant.  The main problem with this strategy is that
there is no longer time to build large systems.

A simple rule of thumb based on function point metrics
indicates the maximum size of applications which can be
built between now and the end of the century.  Raise
the size of the planned application in function points
to the 0.4 power and the result will be the approximate
number of calendar months from requirements to
delivery.  Since there are about 24 months until the
end of the century, applications larger than about 2500
function points can't be completed (this is roughly
equivalent to 250,000 COBOL statements.)  Note that
every month this maximum size will decline.

REQUIREMENTS-BASED TESTING

Designing tests based on objectives derived from
requirements for the software component (e.g., tests
that exercise specific functions or probe the
non-functional constraints such as performance or
security).  See functional test case design.(BCS)

RESULT

See outcome.

RESERVED DATES

These are dates with special meaning such as using 9999
in a year field signifying an entry in a database that
never expires.  They consist of special values that are
equivalent in their type to dates, but are composed of
non-date values such as spaces, 000000, or 999999 in
date fields.  Reserved Dates have been used frequently
in the past to represent items that never expire, or
have other special meanings.
(IEEE)

REVIEW

A process or meeting during which a work product, or
set of work products, is presented to project
personnel, managers, users or other interested parties
for comment or approval. [ieee]

ROLLING WINDOW.

Synonymous with SLIDING WINDOW. (IBM)

RTC

See REAL TIME CLOCK

RTC/CMOS COMBO

See BIOS/CMOS/RTC COMBO