Using The Undokey - Canon Cat Reference Manual

Using the UNDO Key
[UNDO]
undoes or cancels the
previous
operation. Its
use
is described
throughout
the Re/e
rence Guide in relation to
particular
features
of
the Cat. For information
about
[UNDO]
and
a
command, refer
to the part of
the manual
describing
that command,
or to
the index.
Generally
speaking,
[UNDO] can
undo erasing, leaping,
moving text,
highlighting,
and most commands.
[UNDO]
itself
can
be
undone. Pressing
[UNDO]
twice
in
a
row
causes [UNDO]
to undo
itself
and
leaves
the
text
as
it
was before
you
pressed [UNDO]. Continuing
to
press
[UNDO] causes the
text to alternate between
its
"done" and
"undone"
states.
You
can
only undo the previous operation.
You
cannot
backtrack through history, undoing many
operations one
after the other.
If
you press
[UNDO]
at
the end
of
[LEARN],
only the last
operation
performed
by
[LEARNI
will
be
undone.
If
you press any key other than
[UNDO]
or
[EXPLAIN]
after
performing
an operation,
you
cannot undo the operation.
[UNDO] has
no effect on
[DISK],
or on typing.