Folks,

I'm seeing really weird BitBlt artefacts on my Windoze machines, and I can't fix it myself. The following is reproducible on all my machines, systems (NT/98) and VMs (3.0bld2, 3.0bld1, even 2.8bld-a2). I'd be curious whether Mac and Unix users get this, too:

Open a *vanilla* 3.0final image, and do not move, collapse nor obscure the "Welcome" window. Open a workspace and do:

| p q | p _ 394@261. q _ p + (200@0). Display copy: (p extent: 100@100) from: Display to: q rule: 3.

and whip out a MagnifierMorph to examine the result. Here, the first two columns look rather odd. (The "f" of the "for" is missing many bits, while the "e" of the "The" is compressed horizontally.)

I thought I was hallucinating -- this couldn't be, someone would have noticed long ago. But the nastiness nastily varies with Squeak's bit depth. With a graphics card in 32bit mode, the Squeak modes behave as follows:

32 bit: effect is hardly noticeable, the "e" is copied, but 1 bit shorter (top line: 2 pixels instead of 3),

16 bit: the "e"'s top line is only 1 pixel wide,

8 bit: the "e" is crippled,

4 bit: the "e" is copied intact, but now the "o" of the "for" is missing completely,

1 bit: perfect.

I have rummaged through my archive, and a 2.5 VM (win build 6) with an accompanying 2.5f1543 does not show these artefacts, at any bitdepth.

Cheers, Helge