PROBLEMS SPECIFIC TO ZigZag-Gzz
Theodor Holm Nelson
Founding Designer, Project Xanadu
Note: "ZigZag" is a registered trademark of Project Xanadu.
[I know I've written this a dozen times,
but no way to track it.)
0. I find that Gzz runs better in Windows than the Mac,
specifically because in Windows you can hold down
the U key (Undo) and watch it run fast, undoing
the previous instructions; whereas running it on the Mac
you must press U for each undo operation.
1. EDITING TEXT IN A GZZ CELL
9 G This sends left cursor to "Edithack" cell
(the Edithak cell was added for us by still-friendly
member of the Gzz team)
-- this is because Sun changed Java,
making previous edit-mode toggle not work (TAB)
This executes Edithack cell,
causing a new window to open.
This window tracks what's under the blue cursor.
To edit a particular cell, the blue cursor must be on it;
This requires ping-ponging between
ZZ mode (with that window in background)
and editing mode (with edit window selected)
In Windows, OPTION-TAB is the quickest way
to switch between the edit window and the
Be careful-- it's easy to edit text in the wrong cell.
You can actually back up while you're running.
Just make a copy of the current ZigZag directory
(such as "Adam'sRoyals") by selecting and pulling--
- in Windows, ctrl-PullWithMouse
- on Mac, option-PullWithMouse
and then rename the copy something appropriate,
such as "MyTricks-Version3" or "Adam'sRoyals4".
Then if you find you must revert to an earlier
A. Exit the program (with "Q")
B. delete the current version ("MyTricks"
C. make a copy of your latest backup,
D. change ITS name to "MyTricks" or
E. Reopen the program.
3. THE MESSAGE OF DEATH
You may see the words RASTER ERROR
across your screen.
That's it. You're dead. You're hosed.
This can happen for unknowable reasons,
or because you used some dangerous view
(I forget which they are).
Some operations, like Exchange Cursors
(I forget the Gzz key for that)
tend to bring this on.
Worse, this can be based on what you did
some time ago, and one or two previous
backups may be corrupted.
THE LESSON: BACK UP EARLY AND OFTEN.