Karl Baron4d ago

Announcing my third #MARCHintosh 2026 project - the MARCHintosh Canvas!

If you're familiar with Reddit's /r/place, pxls space, or Wplace, you’ll know what this is - a shared canvas anyone can place pixels onto in real-time.

Only this time, it's over the venerable AppleTalk protocol, with the public server accessible to anyone on #GlobalTalk :)

Feel free to drop by and leave your mark - available in the usual places (landisk, Blackbird) on BaroNet

#VintageApple #RetroComputing #mb

Show threadtheirongiant4d ago
@kalleboo - I got those screenshots you asked for about the Type 1 crash. I have WindowShade capability installed on this System 7 Mac. With the FatBits canvas open, if I double-click the window title bar to collapse the canvas, then double-clicking to expand the canvas will cause the crash. This is occurring 100% of the time. Notably, it does not happen if FatBits window is closed, or if I press the dedicated WindowShade button. Only double-clicking seems to trigger it.
Show threadKen McLeod4d ago
@theirongiant @kalleboo Based on that screenshot, it looks like the crash occurs because something in CanvasWGetState attempts to access a field of the canvas window, and is dereferencing a nil handle. Doesn't WindowShade work by setting the visRgn to nil or something along those lines? What status is it accessing?
Show threadKarl Baron4d ago
@_the_cloud @theirongiant Could WindowShade be messing with RefCon? I think that’s where I’m stashing my pointer
Show threadKen McLeod4d ago
@kalleboo @theirongiant That could be it. My really, really dim memory is that the WindowShade INIT sets some region of the window to nil (or an empty region) and it would make sense that they stash the old region somewhere else while it's collapsed.
Show threadtheirongiant
@_the_cloud @kalleboo - still crashes on 1.0.1 D2. See video.
Mar 17 at 6:45amWeb
Show threadKarl Baron4d ago
@theirongiant @_the_cloud Such a weird crash! Thanks for testing
Show threadtheirongiant4d ago
@kalleboo @_the_cloud - so, uh, I was able to reproduce the crash again this morning by doing the WindowShade double-click thing on the FatBits window, not just the main window.