[self-interest] Digest Number 116

[Mario Wolczko]

Stefan Matthias Aust writes:
> Squeak notices if there's an error when it tries to display a morph.  In 
> that case, a special flag is set so that this display method isn't called 
> again until somebody fixes the problem and manually resets that flag.  A 
> flagged morph is displayed as a gray box with two crossing red lines.

This is exactly what Self does (except for the gray box and red lines)
- Randy and I put this code into 4.0, in '95 (before Squeak).  See our
CACM paper (vol 4, #4).  When it was built, the UI was pretty robust
-- we had numerous sessions with multiple users in the world at the
same time, doing development.  Randy and I demo'd this at ECOOP 95.
If it's fragile now, it's because bitrot has set in somewhere, not
because there is an inherent problem.

Jecel writes:
> For 32 bits, 2G is a positive number for C unsigned variables but a
> negative number for signed ones. I took a quick look at space.c in the
> VM sources but didn't get far enough to see if this could be your
> problem.

The VM has no idea how much real memory is installed.  That certainly
isn't the problem.  

Mario