Apple Macintosh - Page 167

Exploring MacPaint 169
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Figure 6.6. The eraser
MACPAINT AND MEMORY OF EVENTS
The MacPaint document can be visualized as having two
storage areas for inform a tion . These areas are the permanent
image and th e memory of the most recent event.
The permanent image is the area holding all picture
information. The memory of the most r ecent event holds the
information for the most recent action tak en with th e picture.
Since th e Mac remembers the pr eced ing action, it can r eve rse
that action. The operator can use the Undo command in the
Edit menu to exp loit thi s feature. Assuming no action was
taken since the eras ure, the action is rever sib le . Sel ecting Un do
from the Edit menu will restore the action. Selecting Undo
again will reerase th at port i on of the drawing. To erase further
now would mak e it impo ssible to undo the first ac tion. Only
the most rec e nt action taken with the drawing is reversible.