HP 54501A Programming Reference Manual page 3

Printing History
New
editions are complete revisions
of the manual.
Update packages,
which are issued between editions, contain additional and replacement
pages
to be merged into the manual
by
the customer. The dates on the
title page change only
when
a
new edition is
published.
A software code may be
printed before
the date; this
indicates the version
of
the software product at the time the manual or update was
issued.
Many
product updates and
fixes
do not require manual changes and,
conversely,
manual corrections may be done without accompanying
product changes. Therefore, do not expect
a
one to one correspondence
between product updates and manual updates.
Edition 1
June 1989 54501-90907