Patch 8*24 GC Control Panel for Compatibility with Drag & Drop?

[olePigeon]

I have another 8*24 GC question. Apparently one of the reasons for the 8*24 GC's problems with newer systems is that the 8*24 GC control panel is incompatible with the Drag & Drop extension. It will cause all sorts of visual artifacts.

Is this something could be patched and fixed? I'm not sure of the timeline of things in regards to the 8*24 GC and Drag & Drop, because Apple never bother to fix it (or it was unfixable.)

 

[Phipli]

Your difficulty there is like a swiss cheese incident - you're looking for two rare occurrences that are coincident. You want someone who both is able to debug the problem, and who has one of the rarest Nubus video cards.

 

[olePigeon]

I'd be happy to lend a card for this purpose.

 

[jmacz]

I may have found a card, not sure if it's a rev A or a rev B, has same ROM part number as the card hyperneogeo sold on the board a couple years ago.

Anyhow, once I get it (and have some time), will take a look to see if it's clear what's happening. Based on some tech articles I read on the GC acceleration, I'm guessing the artifacts are from the drag and drop extension taking some shortcuts when drawing during drag operations, and this is causing issues as the GC acceleration operates asynchronously. Need to confirm whether the artifacts show up during a drag operation, if so what drawing operations are done during a drag, and whether that scenario can be patched in a straight forward manner. Perhaps changing the drawing operation (resulting in drags being a little bit slower) could work and/or disabling acceleration during drag operations.

 

[jmacz]

I've got the driver installed (v7.0.1) and acceleration enabled. I also have the Macintosh Drag and Drop extension (v1.1) loaded. This is running in my IIfx which is using System 7.1.1. I have it set to millions of colors on a 13" monitor. TattleTech says this card is revision 1 so I assume that's revision A.

I did notice that the animated icon during startup isn't clipped properly and draws outside of the icon when animating the rocket launching.

I see artifacts during some drag operations but also during some XOR drawing operations. Hopefully get some time to take a look further to see which exact operations are causing it.

 

[jeremywork]

A few oddities I'm accustomed to when acceleration is enabled alongside drag and drop:

- Netscape Navigator draws 'Back' in every button across the toolbar.
- Drawing dropdown menus more than once consecutively becomes garbled (e.g. open the control panels menu from the Apple menu, then slide across to the Special menu and slide back in one continuous motion)
- Desktop pattern which has been hidden by a window for a while does not redraw properly when the window is moved (especially when switching contexts several times or opening and closing additional programs while the window stays in background)

 

[adespoton]

Hmm; anyone with the issue happen to have Macsbug installed? This really sounds like two different things are writing to the same memory address.

 

[jmacz]

From what I read in an article, the 8*24GC acceleration handles drawing asynchronously and thus expects applications to be using QuickDraw calls which have all been trapped. If any application writes directly to the frame buffer, you get issues.